16)Assume X and Y have a strong positive linear relationship. Then the correlation and
the slope of the regression line will be the same.
a) True
b) False
17)Suppose that a few students hand in their exams very early and that most prefer to
reread their papers and hand them in near the end of the scheduled test period.
Then the mean time taken by students to finish their exams is larger than the
median.
18)The time to complete a standardized exam is approximately normal with a mean of
70 min and a standard deviation of 10 min. How much time should be given to
complete the exam so that 80% of the students will complete the exam in the time
given?
19)
X
has some unknown distribution with mean 10 and standard deviation 5. What do
we know (if anything) about the distribution of
x
?
20)You can use the normal distribution to approximate a binomial distribution when the
following conditions are met:
a)
np ≥ 10 and np(1p) ≥ 10
b)
np ≥ 10 and n(1p) ≥ 10
c)
n ≥ 10 and p ≥ 10
d)
np ≥ 10 or n(1p) ≥ 10
e)
There are no conditions that need to be met
21)
A fair coin (one for which both the probability of heads and the probability of tails are
0.5) is tossed 6 times. The probability that less than 1/3 of the tosses are heads is:
4
This preview has intentionally blurred sections. Sign up to view the full version.
View Full Document
22)Which of the following is needed before you carry out a regression analysis?
23)Suppose a recent survey found that the amount of vitamin C people report taking
daily is strongly negatively correlated with the number of colds they report getting in
a given year. You can conclude from this that vitamin C causes a reduction in colds.
24)A survey asks a random sample of 1500 adults in Ohio if they support an increase in
the state sales tax. Let X denote the number in the sample that say they support the
increase. Suppose that 40% of all adults in Ohio support the increase. What is the
standard deviation of X?
a) 18.97
b) 26.69
c)
75
d) 360
e)
None of the above
This is the end of the preview.
Sign up
to
access the rest of the document.
 Winter '12
 Johnson
 Statistics, Normal Distribution, Standard Deviation

Click to edit the document details