(Using the TI-83/84, we have invNorm(0.8) = 0.8416 .)
From Chapter 5
The correct answer is (a). Discrete data are countable; continuous data correspond to intervals or
measured data. Hence, speed, average temperature, and wingspan are examples of continuous data.
The number of outcomes of a binomial experiment and the jersey numbers of a football team are
countable and, therefore, discrete.
- From Chapter 7
The correct answer is (d). The slope of the regression line. –0.6442, can be found under “Coef” to
the right of “x .” The intercept of the regression line, 22.94, can be found under “Coef” to the right of
“Constant.” - From Chapter 13
The correct answer is (b). The t statistic for H 0 : β = 0 is given in the printout as –1.18. We are given
that n = 10 df = 10 – 2 = 8. From the df = 8 row of Table B (the t Distribution Critical Values
table), we see, ignoring the negative sign since it’s a two-sided test,
1.108 < 1.18 < 1.397 2(0.10) < P < 2(0.15),which is equivalent to 0.20 < P < 0.30. Using the TI-83/84, we have 2 × tcdf (-100, – 1.18,8) =
0.272.
From Chapter 12
The correct answer is (a). The statement is basically a definition of P -value. It is the likelihood of
obtaining, by chance alone, value as extreme or more extreme as that obtained if the null hypothesis
is true. A very small P -value sheds doubt on the truth of the null hypothesis.
- From Chapter 14
The correct answer is (b). Because the samples of men and women represent different populations,
this is a chi-square test of homogeneity of proportions: the proportions of each value of the
categorical variable (in this case, “pro-choice” or “pro-life”) will be the same across the different
populations. Had there been only one sample of 50 people drawn, 25 of whom happened to be men
and 25 of whom happened to be women, this would have been a test of independence. - From Chapter 8
The correct answer is (c). This is a voluntary response survey and is subject to voluntary response
bias. That is, people who feel the most strongly about an issue are those most likely to respond.
Because most callers would be fans, they would most likely blame someone besides the team. - From Chapter 11
The correct answer is (c). The “recipe” we need to use is n ≥ . Since we have nobasis for an estimate for P * , we use P * = 0.5. In this situation the formula reduces to