1. Before the null hypothesis can be rejected at a given level of significance, observed values of t (as compared to those for z)
must deviate further from zero
needn't deviate as far from zero
must deviate the same distance from zero
you must be crazy
2. In reference to the previous question, t scores are different from z scores because we have introduced
a virus
a correction of errors
ourselves
d. another source of error
3. Given a decision rule using critical z scores of ± 1.96 and an observed z value of -2.40, the appropriate decision is to
retain the null hypothesis
reject the null hypothesis
neither reject nor retain, but increase the sample size
neither reject nor retain, but conduct another investigation
4. The null hypothesis
is tested indirectly
makes a claim about a range of values
usually asserts that nothing special is happening
is the interesting question
5. The null hypothesis
a. Supports the research hypothesis
b. Contradicts of research hypothesis
c. Reflects the true state of affairs
d. Reflects the truth most of the time
6. If the null hypothesis is really false and we reject the null hypothesis, we have made a
a. Mistake
b. Correct decision
c. Type I error
d. Type II error
7. The probability of a type I error equals
a. Alpha
b. One minus alpha
c. Beta
d. One minus beta
8. Type II errors are sometimes referred to as
a. False alarms
b. Wild goose chases
c. Misses
d. All of the above
Questions 9 and 10 refer to a personal computer manufacturer. They regularly order printed circuit boards. They like to keep the defect level at 6%. So any shipment that contains more than 6% defective boards is rejected. The null hypothesis asserts that all shipments have 6% defective boards.
9. A type I error occurs whenever
a. A shipment of printed circuit boards with 8% defects is accepted
b. A shipment of printed circuit boards with 4% defects is accepted
c. A shipment of printed circuit boards with 8% defects is rejected
d. A shipment of printed circuit boards with 4% defects is rejected
10. A type II errors occurs whenever
a. A shipment of printed circuit boards with 8% defects is accepted
b. A shipment of printed circuit boards with 4% defects is accepted
c. A shipment of printed circuit boards with 8% defects is rejected
d. A shipment of printed circuit boards with 4% defects is rejected