1 points QUESTION 4

1. A spelling test was given to all first-year statistics students in a large university. The scores from two random samples are shown in the following table.

   	Males	Females
   mean	75.1	78.1
   variance	103.9	90.6
   sample size	40	50

   Which one of the following statements describes correctly the results of a hypothesis test of the claim there is a difference between the mean scores obtained by first-year male and female statistics students at the 5% level of significance ?

   Do notreject the null hypothesisand conclude that there is no difference in the mean scores.

   Do notreject the null hypothesisand conclude that there isa difference in the mean scores.

   Reject the null hypothesisand conclude that there is no difference in the mean scores.

   Reject the null hypothesisand conclude that there isa difference in the mean scores.

1 points QUESTION 5

1. A famous brand-name of soap was advertised with a well-known TV commercial. The company decided to try a new commercial. The test was conducted in the Northern Rivers region of New South Wales, and the two commercials were to be alternated on TV in that area. After two weeks of testing, a random sample of people were telephoned and asked about the two commercials. If the new commercial was significantly better than the old standby, then the new one would be adopted. Since the company considered this a serious decision,5% was chosen for the significance level.

   On the basis of the following data, should the company accept the new commerical?

   	Old commerical (O)	New commerical (N)
   Panel size	100	100
   % recall	35	48

   The null hypothesis and the alternative hypothesis are:

1 points QUESTION 6

1. North Coast traffic police counted the number of drivers booked one day for speeding on the highway.The following table shows the number of drivers booked during each observation period.

   	Observation Period
   	Northbound AM	Southbound AM	Northbound PM	Southbound PM
   	37	37	33	41
   	34	40	34	36
   	38	37	38	40
   	36	42	35	39
   Totals	145	156	140	156

   A significance level of 0.05 is to be used to test the hypothesis that the mean number of drivers booked for speeding is the same for all four periods. The calculated value of the test statistic is closest to:

   16.229

   0.281

   3.557

   4.5625

1 points QUESTION 7

1. A bank manager would like to determine whether the average monthly balance of credit card holders is equal to $750.

   An auditor selects a random sample of 100 accounts and finds that the average owed is $830.40 with a sample standard deviation of $236.50. This sample is used to perform an appropriate hypothesis test to test whether the average balance is not $750

   The calculated value (to three decimal places) of the test statistic is

1 points QUESTION 8

1. An Education lecturer claims that the average student watches at least 26 hours of television per week. A Statistics lecturer decides to examine this claim and collects data on 25 randomly selected students' television habits. It is found that the mean number of hours that the 25 students spent watching television was 22.4 hours. It is known that the population standard deviation is eight hours, and population is normal. A significance level of 1% is to be used to test the Education lecturer's claim.The calculated value of the test statistic is closest to:

   t=-2.25

   z=-0.45

   t=-0.45

   z=-2.25