Chapter 6 and 7 test Flashcards
(15 cards)
What is the 68-95-99?7 rule for normal distribution explain how it can be used to answer questions about frequencies of data values in a normal distribution
The rule states that about 68%, 95%, and 99%.7% of the data points in a normal distribution lie within 1,2, and 3 standard deviations of the mean, respectively
Your are required to take five courses, one each in humanities, sociology, science, math, and 8 music courses. How many diffrent sets of five courses are possible?
There are ______ diffrent sets of five courses possible
Equation: 5x2x4x7x8=2240
Scores on the quanatative portion of an exam have a mean of 589 and a standard deviation of 158. Assume the scores are normally distributed. what percentage of strudents taking the quantitive exame score above 629
What percentage of students taking the quantitve exam score above 629?
z=629-589/158 approximately 0.253
p(0.25)=59.87
p(>0.25)=1.0000-0.5987
=0.40134
You toss a coin 1500 times and record the results. You then look through your results and find that at one point you got 13 heads in a row what is the probability of getting 13 heads in 13 tosses should you be suprised to find this streak in your set of 1500 tosses Explain
The probability that a coin comes up heads 13 times in 13 tosses is _____-
Should you be surprised by this streak? explain
P(13H)=(1/2) to the pwer of 13 =1/8192
No because 1500 tosses is so many that it is almost inevitable that a long streak will occur
A box contains 20 chocaltes but only two of them are the dark chocolate that somebody likes. When it is said that the probality of drawing pne of the dark chocolates at random is 0.1 what kind of probability is being stated.
a theoretical probability because both the total and desired numbers of objects known
I examined the data carefully and the range was greater than the standard deviation
The statement makes sense because the range is approximately four times the standard deviation
Exam results for 100 students are given below. Briefly describe the shape and variation of the distribution.
median=75 mean=75 low score=60 high score=90
Describe the shape of the distribution
The distribution is symmetric because the median is equal to the mean.
The difference between the greatest and the least score is 30, which is small compared to the number of students.
Equation = 90-60=30
Weights in pounds of randomly selected 50 pound bags of dog food are shown below. Compute the mean , median, and the mode of the data set
The mean is 49.74 pound
The meadian is 50 pounds
There is no mode
Use the at least one rule to find the probalitites of trhe following events
1-(1/2) to the power of 7
1-1/128
128-1/128
Answer 127/128
In 8 tosses of a fair coin, should you be surprised to see three tails in 800 tosses of a fair coin, should you be surprised to see 300 tails Explain in terms of the law of large numbers
3_____No, it is not surprising because the small sample size can account for the difference between the expected and actual values
300 tails ___ yes, it is surprising because there are a large number of tosses With a larger number of tosses, the actual probability should approach the theoretical probability
Dtermine whtere the following individual events are overlapping or non overlapping then find the probability of the combined event
Drawing a 3 or a p=spade from a regular deck of cards.
p(3 or spade)=p(3)+p(spade)-p(3 of spades)
= 4/52+13/52-1/52
=16/52=4(4)/4(13)=4/13
Overlapping
Define the five-number summary and explain how to depict it visually with a boxplot.
Which five numbers are included in the five-number summary for a data set
Explain how to depict the five numbers visually with a boxplot. choose correct below
Low value, Lower quartile, median, upper quartile, and high value
Draw a number line that spans all the values in the data set. Enclose the values from the lower to the upper quartile in a box. Draw a vertical line through the box at the median, and add whiskers extending to the low and high values
state whether and why or why not you would expect each of the followsing data sets to be normally distributed
The weights of bags of flour labled 25 pounds
This data set is expected to be normally distributed. The weights should be expected to cluster around 25v pounds and become less common farther from 25 pounds in either direction
Purcahsing 5 winning lottery tickes in a row when each ticket has a 1 in 5 chance of being a winner
p(5 wins)=(1/5) to the power of 5 =1/5 power of 5 =1/5x5x5x5x5=125/3125
