QUESTIONS AND CORRECT ANSWERS
Which of the following describes the standard deviation? - CORRECT ANSWER It is the
square root of the variance.
When two variables are highly positively correlated, the correlation coefficient will be _______. -
CORRECT ANSWER close to 1
According to statistical notation, what does ∑ stand for? - CORRECT ANSWER to act as a
summation operator
The ________ is the observation that occurs most frequently. - CORRECT ANSWER mode
The difference between the first and third quartiles is referred to as the ____________. - CORRECT
ANSWER interquartile range
Which of the following is an example of a measure of dispersion? - CORRECT
ANSWER variance
Which of the following describes a positively skewed histogram? - CORRECT ANSWER a
histogram that tails off toward the right
Which of the following is true for a median? - CORRECT ANSWER For an even number of
observations, the median is the mean of the two middle numbers
Which of the following is an example of a sample? - CORRECT ANSWER The number of IT
employees out of all employees working in an office of Google
For a normal distribution mean is _______ to median. - CORRECT ANSWER equal
When sample size increases
, Correct - CORRECT ANSWER Confidence interval decreases
Which of the following proposition describes an existing theory or belief? - CORRECT
ANSWER Null hypothesis
Which of the following is a Type-I error? - CORRECT ANSWER The null hypothesis is
actually true, but the hypothesis test incorrectly rejects it.
In order to reject the null hypothesis, the p-value must be less than the - CORRECT
ANSWER Alpha
What is the confidence interval when the level of significance is 0.07? - CORRECT
ANSWER 0.930
The WPC Sports Company has noted that the size of individual "customer order" is normally
distributed with a mean of $100 and standard deviation of $12. If a soccer team of 16 players were to
make the next batch of orders, what would be the standard error of the mean? - CORRECT
ANSWER 3.00
You are collecting data via an online survey to improve education standard at ASU. Which of the
following methods will not result in data collection bias? - CORRECT
ANSWER Anonymously data collection by hiding ASU brand in the survey question.
The central limit theorem states that if the population is normally distributed, then the - CORRECT
ANSWER Sampling distribution of the mean will also be normal for any sample size
Which of the following is a continuous random variable? - CORRECT ANSWER The time to
complete a specific task
Which of the following is a difference between the t-distribution and the standard normal (z)
distribution? - CORRECT ANSWER The t-distribution has a larger variance than the standard
normal distribution.