Pleaseensure you havereadandunderstoodtheCML Information Sheetplaced on Blackboard under the Course Overview tab and CML Administrative Folderbefore you begin this quiz.

Ifyou calculate a negative answer youmustput the minus sign in your answer on Blackboard.

If you areexplicitly asked to express an answer as a percentage, to 2 decimal places for example, then a calculated probability of 0.24357 would need to have the answer entered as 24.36 (with NO percentage symbol entered).Where the questiondoes notask you to express your answer as a percentage, enter it as a probability with a value between 0 and 1 (i.e. in the above example you would enter in the value of 0.2436 if the question stated to use 4 decimal places).

As instructed and demonstrated during the lectures and tutorials, youmustuse the textbookTable A.5(to find Z values and probabilities) andTable A.7(to find t values) to manually calculate the answers for this quizunless explicitly stated otherwise.Tables A.5 and A.7 are also available on Blackboard under the Learning Resources.Note that if a Z value is calculated and then used to find a probability, the Z value must be rounded to 2 decimal places first to use Table A.5.Only by using Table A.5 in this way will the correct probability be found to answer these quiz questions.For example, if your Z value is 2.7890, you must look up the Z value of 2.79 in Table A.5.

Note: Please noteno questions require you to use Kaddstat to calculate your final answer. Answers generated by Excel and Kaddstat may differ slightly to answers generated by the CML system (as the CML system is based on manual calculations). You mayhowever use Kaddstat to check the magnitude of your answers. If there is any discrepancy between your manually calculated answers and those given by Kaddstat (though both answers should typically be the same), please enter yourmanually calculated answers.

Answers must be submitted by10:00 pm, Monday 25 January 2021. A detailed breakdown of your results will be available after the quiz closes.

Multiple AttemptsNot allowed. This test can only be taken once.Force CompletionThis test can be saved and resumed later.Your answers are saved automatically.

Question Completion Status:

QUESTION 1

1. Which of the following are true when considering the difference between two means?
2. A small numerical value for the test statistic (in absolute terms), relative to the critical value would cast considerable doubt on the null hypothesis.
3. The fundamental nature of both the hypothesis testing and estimation is altered when we are dealing with the difference between two variable means rather than one mean.
4. A large numerical value for the calculated test statistic relative to the critical value (in absolute terms) would result in a decision to reject the alternate hypothesis.
5. Assume that we select independent samples from two normally distributed populations. If the sample means and standard deviations are known, then in order to test the difference between the population means we assume that the two population variances are equal.

3 points

QUESTION 2

1. A university administrator believes that more than 30% of full-time staff regularly use public transport to travel to the university. In a survey of 70 full-time staff, 27 indicated that they regularly use public transport. On the basis of this evidence, the administrator would
2. not reject the null hypothesis at the 10% level.reject the null hypothesis at the 10% level but not at the 5% level.reject the null hypothesis at the 5% level but not at the 10% level.reject the null hypothesis at the 5% level but not at the 1% level.

2 points

QUESTION 3

1. A wholesaler buys pre-packed sugar in bags with an advertised mean weight of 5 kgs. He wishes to conduct a hypothesis test to check the validity of the advertised weight. Which of the following alternative hypotheses is appropriate?
2. Ha:= 5 kg (equal to)Ha:< 5 kg (less than)Ha: 5 kg (not equal to)Ha:> 5 kg (more than)

2 points

QUESTION 4

1. A member of the Islip Urban Renewal Taskforce claimed, after the installation of internal heating facilities in homes, the proportion of homes with fireplaces fell below 50%.
2. 1. State the direction of the alternative hypothesis used to test the taskforce claim. Type gt (greater than), ge (greater than or equal to), lt (less than), le (less than or equal to) or ne (not equal to) as appropriate in the box.
3. Another committee member, who did not originally believe the claim, took a random sample of 84 houses in the area to test the validity of the claim. He found that 30 of them had fireplaces.
4. 2. Use the tables in the textbook to determine the critical value of the test statistic using a 2% level of significance. If there are two critical values, state only the positive value.
5. 3. Calculate the test statistic, correct to two decimal places.
6. 4. Is the null hypothesis rejected for this test? Type yes or no.
7. 5.Regardless of your answer for 4, if the null hypothesis was rejected, can we conclude after the installation of internal heating facilities in homes, the proportion of homes with fireplaces fell below 50% at the 2% level of significance? Type yes or no.

5 points

QUESTION 5

1. Historically, the average waiting time spent in a queue on Friday afternoon at a bank's city branch was 10 minutes. To determine whether their new multi-queuing system constitutes an improvement, a random sample of 15 customers was taken and their waiting time recorded. The results are in the X1 column of the data file P14.12 which can be found in a folder under the CML Quizzes tab. Assume the distribution of waiting times is normally distributed.
2. 1. State the direction of the alternative hypothesis used to test whether there is an improvement in average waiting time. Type gt (greater than),ge(greater than or equal to),lt(less than),le(less than or equal to) orne(not equal to) as required in the box.
3. 2. Calculate the test statistic correct to three decimal places (hint: use Descriptive Statistics to calculated the standard deviation and sample mean).
4. 3. By referring to the appropriate Z or t-table, which of the following four given numbers is most likely to be the actualp-value for the test? Namely, 0.0814, 0.0515, 0.4292 or 0.4306. Enter your chosen number as your answer, using all four decimal places.
5. 4. Is the null hypothesis rejected for this test if a 5% level of significance is used? Type yes or no.
6. 5. Regardless of your answer for 4, if the null hypothesis was rejected, can we conclude that the average waiting time has improved with the new queuing system? Type yes or no.

5 points

QUESTION 6

1. The Colgate company believes its toothpaste is more effective than its leading rival, Aim, in fighting tooth decay. A small scale clinical trial was held with 25 patients using Colgate and 28 using Aim. The results showed that the average and variance of the number of cavities for Colgate was 10.4 and 12.82, respectively, with the results for Aim being 12.6 and 9.66. It is assumed that the population variances are the same and the distribution of the number of cavities for both groups closely approximates a normal distribution. Use an alpha of 0.01.
2. 1. If the hypotheses are to be written in the form of the average of Aim minus the average of Colgate, what is the direction of the alternative hypothesis used to test Colgate's belief. Type the letters gt (greater than), ge (greater than or equal to), lt (less than), le(less than or equal to) or ne (not equal to) as appropriate in the box.
3. 2. Determine the standard error for the difference between means, reporting your answer to three decimal places.
4. 3. Calculate the test statistic, reporting your answer to two decimal places.
5. 4. Is the null hypothesis rejected for this test? Type yes or no.
6. 5. Regardless of your answer for 4, if the null hypothesis was rejected, can we conclude that Colgate's belief is valid at the 1% level of significance? Type yes or no.

5 points

QUESTION 7

1. Claudia Maurva, manufacturer of CM denim skirts, has pitched her advertising to develop a "stylish yet affordable" image for her brand. She is concerned, however, that retailers are undermining this image, and cutting her market share, by pricing them above her recommended retail price of $49.95. A random sample of thirty-five fashion outlets who stock her skirts finds that the average price charged is $51.87 with the standard deviation being $6.96.
2. 1. State the direction of the alternative hypothesis used to test the company's claim. Type the letters gt (greater than), ge (greater than or equal to), lt (less than), le (less than or equal to) or ne (not equal to) as appropriate in the box.
3. 2. Use the tables in the text to determine the critical value used to conduct the test, assuming a 5% level of significance. If there are two critical values, state only the positive value.
4. 3. Calculate the test statistic (two decimal places).
5. 4. Is the null hypothesis rejected at the 5% level of significance? Type yes or no.
6. 5. If in fact the retailers are charging $51.95 on average, determine the nature of the decision made in the test. Type cd (correct decision), 1 (a Type I error was made) or 2 (a Type II error was made) as appropriate.
7. 6. Regardless of your answer for 4, if we failed to reject the null hypothesis, could we conclude that fashion outlets seem to be charging more than the recommended retail price? Type yes or no.

6 points

QUESTION 8

1. Theowner of a coffee shop has found that the amount spent by customers at the shop is normally distributed with a mean of $6.80 and a standard deviation of $1.20.If a random sample of 25 customers is selected, what is the probability that the average amount spent by this sample of customers will be between $6.50 and $7.40?
2. 0.9938
3. 0.8944
4. 0.8882
5. 0.1056

1 points

QUESTION 9

1. An airline research department measures the weight of a randomly selected 400 unaccompanied luggage bags which were checked in various airports across Australia. It is found the sample mean and sample standard deviation to be 29.88 kgs and 2.4 kgs respectively. The lower limit of a 95% confidence interval for the population mean weight (in kgs) of unaccompanied luggage bags is estimated to be _____________ (2 decimal places)