Test Flashcards
1
Q
What is the primary distinction between data and information?
A
Data is basic values or facts, while information is data that has been organized and/or processed to solve a problem.
This distinction is relative to the needs of the user.
2
Q
What are the different types of data that computers manage?
A
- Numbers
- Text
- Audio
- Images and graphics
- Video
Computers are multimedia devices that handle various information categories.
3
Q
How is all data ultimately stored on a computer?
A
As binary digits (strings of 1s and 0s).
Each document, picture, and sound bite is represented in binary.
4
Q
What is data compression?
A
Reducing the amount of space needed to store a piece of data.
Compression is crucial for efficient storage and sharing of data.
5
Q
What is the purpose of the compression ratio?
A
It indicates how much compression occurs, calculated as the size of compressed data divided by the size of the original data.
The ratio should result in a number between 0 and 1.
6
Q
What is the difference between lossless and lossy data compression?
A
- Lossless: Data can be retrieved without losing any original information.
- Lossy: Some information is lost during compaction.
In some cases, losing information may be acceptable.
7
Q
True or False: The closer the compression ratio is to zero, the tighter the compression.
A
True.
A lower ratio indicates better compression.
8
Q
Fill in the blank: Data compression techniques involve a tradeoff between _______ and size.
A
[accuracy]
This tradeoff is a key consideration in data representation and compression.
9
Q
What motivates the need for efficient data representation in modern computing?
A
The need to share data over networks with inherent bandwidth restrictions.
Streaming video is a significant factor in this need.
10
Q
What is the natural world characterized by?
A
The natural world is characterized by being continuous and infinite.
11
Q
How is a number line described in terms of continuity?
A
A number line is continuous, with values growing infinitely large and small.
12
Q
What can always be done between two integers?
A
You can always find a number that is larger or smaller than any given number.
13
Q
What happens when you divide any number?
A
Any number can be divided in half.
14
Q
What is the theoretical concept related to distance and walls?
A
You could always close the distance to a wall by half and never actually reach it.
15
Q
What is a key difference between computers and the natural world?
A
Computers are finite, while the natural world is infinite.
16
Q
What limits do computers face in data representation?
A
Computer memory and hardware devices have limited room to store and manipulate data.
17
Q
What is the goal of data representation in computing?
A
The goal is to represent enough of the world to satisfy computational needs and senses.
18
Q
What are the two ways data can be represented?
A
Data can be represented as analog or digital.
19
Q
Define analog data.
A
Analog data is a continuous representation, analogous to the actual information it represents.
20
Q
Define digital data.
A
Digital data is a discrete representation, breaking the information into separate elements.
21
Q
Give an example of an analog device.
A
A mercury thermometer is an example of an analog device.
22
Q
How does a mercury thermometer indicate temperature?
A
The mercury rises in a continuous flow in direct proportion to the temperature.
23
Q
How are the markings on a mercury thermometer calibrated?
A
The tube is calibrated and marked to read the current temperature, usually as an integer.
24
Q
What is a limitation of the mercury thermometer’s markings?
A
The markings are not detailed enough to note small changes, like 74.568 degrees Fahrenheit.
25
Fill in the blank: Data can be represented in one of two ways: _______ or digital.
analog
26
What is the primary reason for using the binary system in modern computers?
Binary values are less expensive and more reliable for storage and management.
27
What are the two possible values represented in the binary system?
0 and 1.
28
What is the difference between analog and digital signals?
Analog signals fluctuate in voltage, while digital signals have only high or low states.
29
Fill in the blank: The behavior of digital signals that allows them to maintain integrity despite degradation is known as _______.
pulse-code modulation (PCM)
30
True or False: Information is lost immediately when an analog signal begins to degrade.
True.
31
What happens to a digital signal when it is reclocked?
It regains its original shape.
32
How does the degradation of digital signals differ from that of analog signals?
Digital signals can tolerate more degradation before losing information.
33
What is the effect of environmental factors on electronic signals?
It causes fluctuation in voltage.
34
In what way can digital signals maintain their integrity longer than analog signals?
Digital signals use a threshold to determine high and low values.
35
What is the significance of reclocking digital signals?
It prevents information loss by restoring the signal before too much degradation.
36
What is the inherent nature of using binary?
One bit can be either 0 or 1.
## Footnote
There are no other possibilities in binary representation.
37
How many classifications can one bit represent?
Two classifications.
## Footnote
For example, sweet or sour.
38
What do two bits represent?
Four classifications.
## Footnote
The combinations are 00, 01, 10, and 11.
39
How can two bits be used to represent the gears of a car?
Park (00), Drive (01), Reverse (10), Neutral (11).
## Footnote
The mapping can vary based on preference.
40
What is the representation capacity of three bits?
Eight classifications.
## Footnote
This is because three bits can create eight combinations.
41
What is the representation capacity of four bits?
Sixteen classifications.
## Footnote
Four bits generate 16 combinations.
42
How many classifications can five bits represent?
Thirty-two classifications.
## Footnote
Five bits yield 32 combinations.
43
Fill in the blank: One bit can represent _______.
Two things.
44
True or False: Two bits can represent three classifications.
False.
45
Fill in the blank: Four bits can represent _______.
Sixteen things.
46
How many unique things can n bits represent?
2^n things
## Footnote
This is because n bits can create 2^n combinations of 0 and 1.
47
What happens when the number of available bits is increased by 1?
The number of things we can represent doubles.
48
How many bits are needed to represent 25 unique things?
At least 5 bits
## Footnote
Four bits can represent only 16 things, while five bits can represent 32 things.
49
What is the minimum number of bits usually allocated for storage in computer architecture?
A power of 2, such as 8, 16, or 32 bits.
50
True or False: It is common to allocate fewer bits than necessary for data representation.
False.
51
Fill in the blank: The minimum amount of storage given to any type of data is allocated in multiples of _______.
a power of 2.
52
What is a characteristic of bit combinations in relation to unique items?
Some combinations may not have a valid interpretation.
53
What is the most prevalent type of data used in a computer system?
Numeric values
## Footnote
Numeric data includes both positive and negative integers as well as non-integer values.
54
How is a natural relationship established between numeric data and binary values?
Because binary is a number system
## Footnote
This relationship is particularly evident in the representation of positive integer data.
55
What basic issues regarding numeric data representation are discussed?
Representation of negative and non-integer values
## Footnote
Integers are just the beginning of numeric data.
56
What is signed-magnitude representation?
A way to represent numbers where the sign indicates positive or negative
## Footnote
In signed-magnitude, a negative number has a minus sign in front.
57
What is the visual representation of signed-magnitude numbers?
A number line with negative numbers to the left of zero and positive numbers to the right
## Footnote
Example: -5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5.
58
What is a problem with signed-magnitude representation?
There are two representations of zero: +0 and -0
## Footnote
This can create unnecessary complexity in computer systems.
59
True or False: Negative zero is a commonly accepted concept in mathematics.
False
## Footnote
While negative zero exists in signed-magnitude representation, it is often ignored.
60
Fill in the blank: The signed-magnitude representation allows for two representations of _______.
zero
## Footnote
These representations are +0 and -0.
61
What operations can be performed with signed integer numbers?
Addition and subtraction
## Footnote
These operations can be visualized as moving along a number line.
62
How do you add two signed-magnitude numbers?
Find the first number on the scale and move in the direction of the sign of the second number
## Footnote
The movement is determined by the number of units specified.
63
What does subtraction in signed-magnitude representation involve?
Moving along the number line as dictated by the sign and the operation
## Footnote
Similar to addition, but in the opposite direction.
64
What is the representation of fixed-sized numbers?
Numbers are represented as integer values, with half for negative numbers
65
In a fixed-sized number scheme with two decimal digits, how are positive and negative numbers represented?
1 through 49 are positive (1 to 49), 50 through 99 are negative (-50 to -1)
66
How is the sign of a number determined in the fixed-sized number scheme?
By the magnitude of the number
67
What happens to carries during addition in the fixed-sized number scheme?
Carries are discarded
68
What is the result of adding the positive number 5 and the negative number -6 in the fixed-sized number scheme?
99
69
What is the result of adding -1 and -4 in the fixed-sized number scheme?
94
70
How can subtraction be performed in the fixed-sized number scheme?
By adding the negative of the second number to the first
71
What is the equation that represents the relationship between addition and subtraction?
A - B = A + (-B)
72
What is the result of subtracting 8 from -5 using the fixed-sized number scheme?
92
73
Fill in the blank: In the fixed-sized number scheme, adding two negative numbers results in _______.
a negative number
74
True or False: In the fixed-sized number scheme, all negative numbers are represented by values greater than 50.
True
75
What does the term 'signed-magnitude' refer to?
A way to represent positive and negative numbers
76
What is the formula to compute the negative representation of a number?
Negative (1) = 10k - 1, where k is the number of digits
## Footnote
This formula allows for calculating the negative representation in a fixed size number system.
77
How is -3 represented in a two-digit representation using the ten's complement?
97
## Footnote
The calculation is done using the formula: 10^2 - 3 = 97.
78
How is -3 represented in a three-digit representation using the ten's complement?
997
## Footnote
The calculation is done using the formula: 10^3 - 3 = 997.
79
What is the ten's complement?
A representation of negative numbers in a fixed size number system
## Footnote
It simplifies calculations, especially in electronic systems.
80
What is the binary equivalent of the ten's complement called?
Two's complement
## Footnote
This is used for representing negative numbers in binary systems.
81
In an eight-bit representation, how many bits are used for the number and how many for the sign?
Seven bits for the number and one bit for the sign
## Footnote
This structure allows for both positive and negative number representations.
82
True or False: The ten's complement is easier for human calculations than sign and magnitude.
False
## Footnote
While humans think in sign and magnitude, the complement strategy is easier for electronic calculations.
83
Fill in the blank: The two's complement is used to represent negative numbers in _______.
binary
## Footnote
This method is essential for modern computer calculations.
84
What representation do humans tend to use for numbers?
Sign and magnitude
## Footnote
This is a common method for understanding numbers, but not the most efficient for electronic calculations.
85
What is the formula to compute the negative representation of a number?
Negative (1) = 10k - 1, where k is the number of digits
## Footnote
This formula allows for calculating the negative representation in a fixed size number system.
86
How is -3 represented in a two-digit representation using the ten's complement?
97
## Footnote
The calculation is done using the formula: 10^2 - 3 = 97.
87
How is -3 represented in a three-digit representation using the ten's complement?
997
## Footnote
The calculation is done using the formula: 10^3 - 3 = 997.
88
What is the ten's complement?
A representation of negative numbers in a fixed size number system
## Footnote
It simplifies calculations, especially in electronic systems.
89
What is the binary equivalent of the ten's complement called?
Two's complement
## Footnote
This is used for representing negative numbers in binary systems.
90
In an eight-bit representation, how many bits are used for the number and how many for the sign?
Seven bits for the number and one bit for the sign
## Footnote
This structure allows for both positive and negative number representations.
91
True or False: The ten's complement is easier for human calculations than sign and magnitude.
False
## Footnote
While humans think in sign and magnitude, the complement strategy is easier for electronic calculations.
92
Fill in the blank: The two's complement is used to represent negative numbers in _______.
binary
## Footnote
This method is essential for modern computer calculations.
93
What representation do humans tend to use for numbers?
Sign and magnitude
## Footnote
This is a common method for understanding numbers, but not the most efficient for electronic calculations.
94
What is the formula for calculating the negative binary representation using ten's complement?
negative(I) = 2k - I
95
What is the result of applying the formula negative(I) = 2k - I for I = 2?
254
96
What is the binary representation of the decimal number 254?
11111110
97
What does the leftmost bit in a binary number indicate?
The sign of the number
98
If the leftmost bit is 0, what does it indicate about the number?
The number is positive
99
If the leftmost bit is 1, what does it indicate about the number?
The number is negative
100
What is the two's complement of a number?
Invert the bits and add 1
101
What are the steps to calculate the two's complement of +2?
* Invert the bits
* Add 1
102
What is the binary representation of +2?
00000010
103
What is the inverted binary representation of +2?
11111101
104
What is the result after adding 1 to the inverted binary representation of +2?
11111110
105
Fill in the blank: The two's complement of +2 is _______.
-2
106
How are addition and subtraction accomplished in two's complement arithmetic?
The same way as in ten's complement arithmetic
107
What does the leftmost bit in a negative number represent in two's complement?
It is always a 1, indicating the number is negative
108
What occurs when the computed value cannot fit into the allocated bits?
Overflow occurs
109
Provide an example of overflow using eight bits.
Adding 127 to 3 produces 10000010, which represents -126 instead of +130
110
What is the classic example of problems encountered by mapping an infinite world onto a finite machine?
Overflow problems
111
How does the handling of overflow problems vary?
It varies by computer hardware and by differences in programming languages
112
What are real numbers in computing?
Non-integer values that can be represented with a potential fractional part
113
What are some examples of real numbers in base 10?
* 104.32
* 0.999999
* 357.0
* 3.14159
114
How are position values determined for digits in base 10?
By raising the base value to increasing powers moving from the decimal point to the left
115
What are the positions to the right of the decimal point in base 10 called?
* Tenths position
* Hundredths position
116
What is the base value used in binary representation?
2
117
What is the term used for the decimal point in bases other than 10?
Radix point
118
What are the positions to the right of the radix point in binary?
* Halves position
* Quarters position
119
How are addition and subtraction accomplished in two's complement arithmetic?
The same way as in ten's complement arithmetic
120
What does the leftmost bit in a negative number represent in two's complement?
It is always a 1, indicating the number is negative
121
What occurs when the computed value cannot fit into the allocated bits?
Overflow occurs
122
Provide an example of overflow using eight bits.
Adding 127 to 3 produces 10000010, which represents -126 instead of +130
123
What is the classic example of problems encountered by mapping an infinite world onto a finite machine?
Overflow problems
124
How does the handling of overflow problems vary?
It varies by computer hardware and by differences in programming languages
125
What are real numbers in computing?
Non-integer values that can be represented with a potential fractional part
126
What are some examples of real numbers in base 10?
* 104.32
* 0.999999
* 357.0
* 3.14159
127
How are position values determined for digits in base 10?
By raising the base value to increasing powers moving from the decimal point to the left
128
What are the positions to the right of the decimal point in base 10 called?
* Tenths position
* Hundredths position
129
What is the base value used in binary representation?
2
130
What is the term used for the decimal point in bases other than 10?
Radix point
131
What are the positions to the right of the radix point in binary?
* Halves position
* Quarters position
132
What is the primary purpose of numerical data representation?
To convey quantitative information in a clear and interpretable manner.
133
Which of the following is a common form of numerical data representation?
Graphs and charts.
134
True or False: Numerical data can only be represented in tabular form.
False.
135
Fill in the blank: A __________ is a graphical representation of data using bars of different heights.
Bar chart.
136
What type of chart is best for showing proportions of a whole?
Pie chart.
137
Which measure is used to describe the central tendency of a data set?
Mean.
138
True or False: The median is always the same as the mean.
False.
139
What is the term for the difference between the highest and lowest values in a data set?
Range.
140
Which of the following represents categorical data?
Nominal scale.
141
Fill in the blank: A __________ is a visual representation that shows the frequency of data points in intervals.
Histogram.
142
What is a scatter plot primarily used for?
To show the relationship between two quantitative variables.
143
Which of the following is NOT a measure of variability?
Mode.
144
True or False: A box plot can be used to identify outliers in a data set.
True.
145
What is the purpose of a line graph?
To display trends over time.
146
Fill in the blank: The __________ is the value that occurs most frequently in a data set.
Mode.
147
Which statistical measure is resistant to outliers?
Median.
148
What does a normal distribution curve represent?
A symmetric distribution where most values cluster around the mean.
149
True or False: The interquartile range (IQR) measures the spread of the middle 50% of a data set.
True.
150
What is the first step in data analysis?
Data collection.
151
Which of the following is a visual tool for comparing parts to a whole?
Pie chart.
152
Fill in the blank: In a __________, data points are plotted along two axes to show their relationship.
Scatter plot.
153
What does the term 'outlier' refer to in a data set?
A value that is significantly higher or lower than the other values.
154
True or False: A histogram can be used to represent categorical data.
False.
155
What is the main feature of a box-and-whisker plot?
It summarizes the distribution of a data set through its quartiles.
156
Which type of graph is best for displaying the frequency of different categories?
Bar chart.
157
Fill in the blank: The __________ is the average of a set of values.
Mean.
