Presentation evaluation:
MINI-TEST: CHAPTER 9
A:
B:
Student’s name:
Liêu Nguyễn Khánh Linh
C:
Multiple choice: choose the one alternative that best completes the statement or answers the question.
1) "My careful physical examination shows no evidence of any serious problem," said Doctor Morpheus. "However, a very costly lab
test can be performed to check for the rare condition known as estomalgia fatalis. The test is almost invariably negative for persons
with your age and symptoms. My personal hypothesis is that the occasional stomach pain you reported is due to indigestion caused by
eating tacos with too much hot sauce. But you must decide for yourself." As you consider your doctor's hypothesis, what would be the
consequence of Type I error on your part?
A) It cannot be determined without knowing the type of test.
B) Your estomalgia fatalis will go undetected.
C) You will waste money on an unnecessary lab test.
D) Your survivors will enjoy a sizeable malpractice award.
2) A study over a 10-year period showed that a certain mammogram test had a 50 percent rate of false positives. This indicates that
A) about half the tests indicated cancer.
B) about half the tests missed a cancer that exists.
C) about half the tests showed a cancer that did not exist.
D) about half the women tested actually had no cancer.
3) For a test of a mean, which of the following is incorrect?
A) H0 is rejected when the calculated p-value is less than the critical value of the test statistic.
B) In a right-tailed test, we reject H0 when the test statistic exceeds the critical value.
C) The critical value is based on the researcher's chosen level of significance.
D) If H0: μ ≤ 100 and H1: μ > 100, then the test is right-tailed.
4) For tests of a mean, if other factors are held constant, which statement is correct?
A) The critical value of Student's t increases as n increases.
B) A test statistic tcalc = 1.853 with n = 16 leads to rejection at α = .05 in a one-tailed test.
C) It is harder to reject the null hypothesis in a two-tailed test rather than a one-tailed test.
D) If we desire α = .10, then a p-value of .13 would lead us to reject the null hypothesis.
5) The critical value in a hypothesis test
A) is derived from the sample.
C) is another name for the null hypothesis.
B) is determined by α and the type of test.
D) is a dissenting view by scientific critics.
Short Answer: write the word or phrase that best completes each statement or answers the question.
6) The process that produces Sonora Bars (a type of candy) is intended to produce bars with a mean weight of 56 gm. The process
standard deviation is known to be 0.77 gm. A random sample of 49 candy bars yields a mean weight of 55.82 gm. Which are the
hypotheses to test whether the mean is smaller than it is supposed to be? Find the p-value for a test to see whether the candy bars are
smaller than they are supposed to be.
1.64
7) Last year, 10 percent of all teenagers purchased a new iPhone. This year, a sample of 260 randomly chosen teenagers showed that
39 had purchased a new iPhone. State the hypotheses to test whether whether the percentage has risen at α = .01.
2.58
8) The researcher's null hypothesis is H0: σ2 ≤ 22. A sample of n = 25 items yields a sample variance of s2 = 28.5. Test the null
hyphothesis at α = .05.
36.415