a) Null: it is not the case that a majority of American Catholics favor allowing women to be priests. Alternative: A majority of American Catholics favor allowing women to be priests.
b) SD = 0.022, standardized score = 4.05
c) reject the null hypothesis, We can conclude that a majority of American Catholics favor allowing women to be priests.
Problem 2.
One sided, because the alternative includes values above 0.50 only.
Problem 3.
Double the value to get 0.06.
Problem 4.
a) No, because 0.08 > 0.05.
b) Yes, because the p-value would be 0.04
Problem 6.
a) 0.03
b) 0.023
c) .0000216
Problem 8.
A Type 1 error would be that there is no relationship,but that the study found one, in which case the law discriminating by ages would have been upheld. A type 2 error would be that there is a relationship but it was not detected, in which case the law was not upheld, but perhaps should have been because young men are more likely to drink and drive than young women.
Problem 14.
a) Null the risk of developing breast cancer is the same for women who had their first child at age 25 or older as is is for women who had their first child before age 25. Alternative: Women who had their first child at age 25 or older have a higher risk of breast cancer than women who had their first child before age 25.
b) the p-value is about 0.19. Do not reject the null hypothesis; we cannot conclude that the risk of breast cancer is higher for women who have their first child after age 25. Rewritten for the statistically naive: in a recent study, women who had their first child after the age of 25 had a higher risk of breast cancer than women who had their first child before age25, but the increase was not large enough to rule out chance as an explanation.
Problem 16.
a) Null: there is no relationship between smoking behavior and time to pregnancy. Alternative: there is a relationship between smoking behavior and time to pregnancy.
b) The p-value is 0.028.
c) No, the p-value is not the probability that the null is true.
d) A type 1 error would mean that there is no relationship but that she concludes there is and stops smoking. A type 2 error would mean that there is a relationship, but she does not recognize that fact and does not sop smoking, when in fact it may help her if she did.
Problem 17.
b) Null hypothesis there is no relationship between gender and driving after drinking alcohol. Alternative: there is a relationship between gender and driving after drinking alcohol.
The test statistic is the chi-square value of 70.43; the p-value is essentially 0.
Problem 18.
a) CI is 0.14 to 1.94kg. The CI is more informative because no only can we tell hat there is a real difference, which the test tells us, but the interval tells us the magnitude of the difference.
b) No, the data would no support that alternative because the dieters lost more fat. so we could not reject the null.
c) Yes, because the data support this alternative. The p-value would be between 0.01 and 0.02 and the standardized score is 2.17.