Which statement makes a correct comparison of their simulated sampling distributions?
A. Both simulated sampling distributions are approximately normal.
B. Both simulated sampling distributions have the same spread.
C. Claire’s simulated sampling distribution is skewed to the right, and Max’s is roughly
symmetric.
D. Claire’s simulated sampling distribution is roughly symmetric, and Max’s is skewed to the left.
E. Claire’s simulated sampling distribution is approximately normal, and Max’s is approximately
a t -distribution.
A spreadsheet contains a data set that consists of 100 values such that IQR > variance . However,
these values must be converted using the following formula: NewValue = 2(OldValue ) + 10. Which
of the following statements is true about the data set consisting of the NewValues?
A. The IQR has been increased by 10 units.
B. The IQR is now less than the variance.
C. The IQR is now double its previous size.
D. The IQR has been doubled and then increased by 10 units.
E. The IQR has been cut in half.
- A test for heartworm in dogs shows a positive result in 96% of dogs that actually have heartworm,
and shows a negative result in 98% of dogs with no heartworm. If heartworm actually occurs in
10% of dogs, what is the probability that a randomly selected dog that tested positive for
heartworm actually has heartworm?
A. 11%
B. 18%
C. 84%
D. 88%
E. 96% - A recent poll reported that 43% of Americans approve of the job the president is doing, with a
margin of sampling error of ±3.2% at a 95% level of confidence. Which of these correctly
interprets that margin of error?
A. There is a 3.2% percent chance that the proportion of all Americans who approve of the job the
president is doing is not 43%.
B. There is a 95% chance that the proportion of all Americans who approve of the job the
president is doing is 43%.
C. About 95% of polls conducted in this way will find that between 39.8% and 46.2% of those
sampled approve of the job the president is doing.
D. About 95% of polls conducted in this way will give a sample proportion within 3.2 percentage
points of the actual proportion of all Americans who approve of the job the president is doing.
E. About 3.2% of all Americans approve of 95% of what the president does. - Two events A and B each have a nonzero probability. If A and B are independent, which of the
following statements is true?
A. P (A and B ) = P (A ) · P (B )
B. A and B may or may not be mutually exclusive.
C. A and B must be mutually exclusive.