Exam 1 Flashcards
(43 cards)
A survey of high school teenagers reported that 89% of those sampled are interested in pursuing a college education. This statement illustrates
Select one:
a. Inferential statistics
b. Descriptive statistics
B. Descriptive Statistics
A company has developed a new computer sound card whose average lifetime is unknown. In order to estimate this average, 200 sound cards are randomly selected from a large production line and tested; their average lifetime is found to be 5 years. The 200 sound cards represent a:
Select one:
a. statistic
b. Parameter
c. population
d. sample
D. Sample
A politician who is running for the office of governor of a state with 4 million registered voters commissions a survey. In the survey, 54% of the 5,000 registered voters interviewed say they plan to vote for her. The population of interest is:
Select one:
a. The 4 million registered voters in the state
b. all the residents of the state
c. the 54% who plan to vote for her
d. the 5,000 registered voters interviewed
A. The 4 million registered voters in the state
You take a random sample of 100 students at your university and find that their average GPA is 3.1. If you use this information to help you estimate the average GPA for all students at your university, then you are doing
Select one:
a. Descriptive statistics
b. Inferential statistics
B. Inferential Statistics
We are living in a world where almost everything is digitalized. For example, every click online is a data observation. Parallel to the explosion of data, computational power of computers have also increased. Hoping to leverage the great deal of information in the data, many organizations have started to appreciate the role of statistics in their decision making process. Graduates of Mihaylo College of Business and Economics majoring in one of the following choices are the best fit to fill in this role. Select one: a. Accounting b. Management c. Marketing d. Business analytics
D. Business Analytics
Which one of the following cannot be used as a measure of spread or variability? Select one: a. Mean b. Standard deviation c. IQR d. Range
A. Mean
Which one of the following is among the likely causes of a non-random sample? Select one: a. Parameter b. Non-response bias c. Statistics d. Population
B. Non-response bias
Which one of the following statements cannot be used as a possible description for
shape of a distribution?
Select one:
a. It has a median of 55
b. It is skewed
c. It is symmetric
d. It is bi-modalA. It has a median of 55
A local TV station conducts an “Instant Poll” to predict the winner in the upcoming mayoral election. Evening news viewers were invited to phone in their votes, with the results to be announced on the late-night news. Based on the phone calls, the station predicted that Amabo would win the election with 52% of the vote. They were wrong: Amabo lost, getting only 46% of the vote. This faulty prediction is more likely to be the result of
Select one:
a. Selection bias as only people watching the news will respond, and their preference may differ from that of other voters
b. Non-response bias as some people are excluded in the sample whose preference may differ from those included in the sample
c. Both A) and B) are plausible explanations
d. None of the above
C. Both A and B
A university was interested in student reaction to a proposal to spend more on athletic scholarships and less on academic scholarships. 35 student athletes were surveyed. What type of problem has occurred?
Select one:
a. Measurement error
b. selection bias
B. Selection Bias
A watchdog group is investigating how people are treated during the foreclosure process.
Surveys were mailed to a random sample of 300 people who had recently been threatened
with foreclosure. 75 of the surveys were returned by postal service because the intended
recipients had moved and left no forwarding address. What type problem has occurred?
Select one:
a. measurement error
b. Non-response bias
c. selection bias
B. Non-response bias
The location of a particular value in a sample (or a population) relative to the mean can be measured by Select one: a. Coefficient of variation (CV) b. Standard deviation c. z-score d. Range
C. z-score
The use of the Empirical rule requires Select one: a. The data to be skewed to the right b. the data to be bimodal c. the data to be skewed to the left d. the data to resemble the normal distribution
D. the data to resemble the normal distribution
Statistics as a data science
Select one:
a. is a science of telling the future
b. is a way of getting data from information
c. is a way of getting information from data
d. is a way of collecting data from various sources
C. is a way of getting information from data
The population size and the sample size is denoted by: Select one: a. σ,s b. N,n c. n,N d. σ,n
B. N,n
In inferential statistics, we seek to infer about
Select one:
a. The population parameter
b. The sample statistics
A. The population parameter
For a boxplot with Q1 = 35, Q3 = 55, median = 48, can a value of 95 be considered an outlier? Select one: a. No b. Yes c. Cannot be determined
B. Yes
For a boxplot with Q1 = 35, Q3 = 55, median = 48, can a value of 10 be considered an outlier? Select one: a. Cannot be determined b. No c. Yes
B. No
A histogram is bi-modal then,
It has two modes
A histogram is symmetric, then
it has no skewness
A histogram of given data shows three clean peaks, therefore
There are three modes and three groups of data
A value has a z score of 3. This means?
The value is three stand and deviations above the mean.
A variable has a Q1 of 25 and a Q3 of 75. It also has a Q2 of 50. What is the IQR?
50
From a random sample of 500 students, students study for an average of 10 hours per week with a standard deviation of 4 hours per week. Say, a student in this sample studies for 12 hours per week. What is the z-score of this student?
0.5
