1) All of the following facts concering the relations of t and z are true except for
a) T curves are more spread out than z curves.
b) T becomes close to z when there is a large n.
c) Z curves are always bell-shaped while t-curves have a bell-shape most of the time.
d) Z has the two variables mean and standard deviation while T has the three variables mean, standard deviation, and
degrees of freedom.
2) For a small n, t is
than z.
a) closer
b) more spread out
c) opposite
d) smaller
3) Why did Gosset invent t*?
a) He thought s>0.
b) He was worried there was more variation in the data.
c) S did not work for a small degrees of freedom.
d) N was not small enough.
e) He was drunk.
4) When n is
, t is more spread out than z.
a) large
b) small
c) the same
d) all of the above
5) Which is a matched paris situation?
a) Half the group gets a placebo and the other half get the actual medication.
b) Through random distribution, half of the people receive Pepsi, and the other half receive Coca-Cola.
c) The people eat both sandwiches, A and B. The order for eaiting A or B is randomly chosen.
6) What is true about the relationship between t and z?
a) As n gets bigger, t becomes closer to z.
b) As n gets smaller, t becomes more spread out than z.
c) None of the above.
d) Both A and B.
7) A manufacturer of small LEGO accessories employs a market research firm to estimate retail sales of its products
by gathering information from a sample of retail stores. This month, an SRS of 100 stores on the West Coast sale region finds
that these stores sold an average of 28 of the manufacturers' products, with a standard deviation of 13. Give a 95% confidence
interval for the mean number of LEGO's sold in the west.
a) (7.4442, 18.556)
b) (25.421, 30.579)
c) (18.556, 7.4442)
d) (-25.421, 30.579)
8) When does t become more like z?
a) When Michael Waller outsmarts Mr. Derksen.
b) When the degrees of freedom increases.
c) When Daniella's fat lard sits on t and z squeezes out.
d) When Jennifer goes on a diet. (Never.)
9) When are the tails of a t curve fatter than those of the z curve?
a) When n is large.
b) When standard deviation is larger.
c) When n is small.
d) When standard deviation is smaller.
e) Always.
SELECTED ANSWERS
1) c 5) c 7) a 8) b 9) e
