1..In a hypothesis test:

(a) the null hypothesis is what we are trying to prove

(b) the alternate hypothesis is always assumed to be true

(c) the alternate hypothesisis accepted unlessthere issufficient evidence to say otherwise

(d) the null hypothesisis notrejected unlessthere issufficient evidence to reject it.

2. Which of the following is TRUE?

(a) the alternative hypothesisrepresentsthe conclusion for which evidence is sought

(b) the statement of the null hypothesis never contains an equality

(c) an increase in the risk of type I error also increasesthe risk of a type II error

(d) the computed test statistic is also known as the critical value.

3. Nestor Milk Powder issold in packets with an advertised mean weight of 1.5kgs. The standard deviation is known to be 184 grams. A consumer group wishes to check the accuracy of the advertised mean and takes a sample of 52 packetsfinding an average weight of 1.49kgs. What is the set of hypotheses that should be used to test the accuracy of advertised weight?

(a) H0: = 1.5; H1: 1.5

(b) H0: = 1.5; H1: < 1.5

(c) H0: x = 1.49; H1: x 1.49

(d) H0: x = 1.5; H1: x <1.5.

4. Mr Rumpole believes that the mean income of lawyers is now more than $65 thousand per year. Which isthe correctset of hypothesesto test this belief?

(a) H0: 65 000; H1: < 65 000

(b) H0: 65 000; H1: > 65 000

(c) H0: = 65 000; H1: 65 000

(d) H0: < 65 000; H1: 65 000

5. Suppose a business person wishes to open a store in a local shopping centre only ifthere isstrong evidence that the average number of people in the centre is greater than 5000 per day. The null hypothesis will be

(a) H0: 5000

(b) H0: > 5000

(c) H0: 5000 (d) H0: < 5000

(e) b or c

6. If a test of a hypothesis has a type I error probability of 0.01, we mean

(a) if the null hypothesis is true, we reject it 1% of the time

(b) if the null hypothesis is true, we don't reject it 1% of the time

(c) if the null hypothesis is false, we reject it 1% of the time

(d) if the null hypothesis is false, we don't reject it 1% of the time

7. In hypothesis testing

(a) rejecting the null might lead to a type II error

(b) = 1 -

(c) a type II error occurs whenever the null hypothesis is accepted

(d) all of the above are incorrect.

8. A tyre manufacturer claimsthat itstyres have a mean life of at least 50 000 kms. A random sample of 16 of these tyres istested and the sample mean is 33 000 kms. Assume the populationsstandard deviation is 3000 kms and the lives oftyres are approximately normally distributed.To test the manufacturer's claim using the 5% level ofsignificance the analyst should

(a) use a one tail test in the right tail and the test statistic Z

(b) use a one tail test in the left tail and the test statistic Z

(c) use a one tail test in the left tail and the test statistic t

(d) use a two tail test and the test statistic t

9. Adrink vendingmachine is adjusted so that, on average, it dispenses 220 mls of fruit juice (with a standard deviation of 10mls) into a plastic cup. However, the machine has a tendency to go out of adjustment and periodic checks are made to determine the average amount of fruit juice actually being dispensed. A sample of 45 drinks is taken to test the adjustment of the machine. For =5%, an appropriate decision rule would be

(a) reject the null if the calculated Z > 1.96

(b) do not reject the null if calc Z is < 1.96

(c) reject the null if the calculated Z 1.96

(d) reject the null if the calculated Z > 1.96

10. Amanufacturer of car batteries claimsthat his product will last at least 4 years on average. A sample of 50 is taken and the mean and standard deviation are found. The teststatistic is calculated to be -1.656. Using a 5% level, the conclusion would be

(a) there issufficient evidence forthemanufacturer's claimto be considered correct.

(b) there isinsufficient evidence forthemanufacturer's claimto be considered correct.

(c) there issufficient evidence forthemanufacturer's claimto be considered incorrect.

(d) there isinsufficient evidence forthemanufacturer's claimto be considered incorrect.

11. If a hypothesisis not rejected at the 5% level ofsignificance is

(a) will never be rejected at the 1% level.

(b) will always be rejected at the 1% level.

(c) will sometimes not be accepted at the 1%level?

(d) there isinsufficient information to say what will happen at the 1% level