Exam 10: One-Sample Tests of Hypothesis

To compare the effect of weather on sales of soft drinks, a soda manufacturer sampled two regions Of the country with the following results. Is there a difference in sales between the 2 regions? i. The null hypothesis is pa - pb = 0. ii. The alternate hypothesis is pa - pb ≠ 0. iii. If α = 0.01 and the z-statistic were calculated to be -1.96, your decision would be to fail to reject.

The employees at the East Vancouver office of a multinational company are demanding higher Salaries than those offered at the company office located in Oshawa Ontario. Their justification for The pay difference is that the difference between the average price of single-family houses in East Vancouver and that in Oshawa is more than $60,000. Before making a decision, the company Management wants to study the difference in the prices of single-family houses for sale at the two Locations. The results of their search of recent house sales are as follows (in $1000, rounded to the nearest Thousand): Assuming that the population distributions are approximately normal, can we conclude at the 0.05 Significance level that the difference between the two population means is greater than $60,000? This example is what type of test?

Accounting procedures allow a business to evaluate their inventory at LIFO (Last In First Out) or FIFO (First In First Out). A manufacturer evaluated its finished goods inventory (in $1000) for five Products both ways. Based on the following results, is LIFO more effective in keeping the value of His inventory lower? If you were to use Megastat to assist in your solution to this problem, which test would you use?

A random sample of 20 statistics students was given 15 multiple-choice questions and 15 open- Ended questions-all on the same material. The professor was interested in determining which type Of questions the students scored higher. This experiment is an example of:

To compare the effect of weather on sales of soft drinks, a soda manufacturer sampled two regions Of the country with the following results. Is there a difference in sales between the 2 regions? i. The null hypothesis is pa - pb = 0. ii. The alternate hypothesis is pa - pb ≠ 0. iii. Using the 1% level of significance, the critical value is ±2.58.

The net weights of a sample of bottles filled by a machine manufactured by Edne, and the net Weights of a sample filled by a similar machine manufactured by Orno, Inc., are (in grams): Testing the claim at the 0.05 level the mean weight of the bottles filled by the Orno machine is Greater than the mean weight of the bottles filled by the Edne machine, what is the critical value?

The employees at the East Vancouver office of a multinational company are demanding higher Salaries than those offered at the company office located in Oshawa Ontario. Their justification for The pay difference is that the difference between the average price of single-family houses in East Vancouver and that in Oshawa is more than $60,000. Before making a decision, the company Management wants to study the difference in the prices of single-family houses for sale at the two Locations. The results of their search of recent house sales are as follows (in $1000, rounded to the nearest Thousand): Assuming that the population distributions are approximately normal, can we conclude at the 0.05 Significance level that the difference between the two population means is greater than $60,000? What is the alternate hypothesis?

Accounting procedures allow a business to evaluate their inventory at LIFO (Last In First Out) or FIFO (First In First Out). A manufacturer evaluated its finished goods inventory (in $1000) for five Products both ways. Based on the following results, is LIFO more effective in keeping the value of His inventory lower? What is the decision at the 5% level of significance?

Of 150 adults who tried a new peach-flavoured peppermint patty, 90 rated it excellent. Of 200 Children sampled, 123 rated it excellent. Using the 0.10 level of significance, can we conclude that There is a significant difference in the proportion of adults and the proportion of children who rate The new flavour as excellent? State the decision rule, the value of the test statistic, and your Decision.

A recent study compared the time spent together by single and dual-earner couples. According to The records kept during the study, the mean amount of time spent together watching TV among Single-earner couples was 55 minutes per day, with a standard deviation of 15.5 minutes. For the Dual-earner couples, the mean time was 48.4 and the standard deviation was 18.1. At a 0.01 Significance level, can we conclude that the single-earner couples on average spend more time Watching TV together? There were 12 single-earner and 12 dual-earner couples studied. State the Decision rule, the value of the test statistic, and your decision.

i. If we are testing for the difference between two population means, it is assumed that the sample Observations from one population are independent of the sample observations from the other Population. ii. If we are testing for the difference between two population means, it is assumed that the two Populations are approximately normal and have equal variances. iii. When sample sizes are less than 30, a test for the differences between two population means Has n - 1 degrees of freedom.

A recent study compared the time spent together by single and dual-earner couples. According to The records kept during the study, the mean amount of time spent together watching TV among Single-earner couples was 61 minutes per day, with a standard deviation of 15.5 minutes. For the Dual-earner couples, the mean time was 48.4 and the standard deviation was 18.1. At a 0.01 Significance level, can we conclude that the single-earner couples on average spend more time Watching TV together? There were 15 single-earner and 12 dual-earner couples studied. State the Decision rule, the value of the test statistic, and your decision.

A company is researching the effectiveness of a new website design to decrease the time to access A website. Five website users were randomly selected, and their times (in seconds) to access the Website with the old and new designs were recorded. To compare the times, they computed (new Website design time - old website design time). The results follow: What are the null and alternative hypothesis?

The results of a mathematics placement exam at Mercy College for two campuses are as follows: If you were to use MegaStat to assist in your solution to this problem, which test would you use?

A company is researching the effectiveness of a new website design to decrease the time to access A website. Five website users were randomly selected, and their times (in seconds) to access the Website with the old and new designs were recorded. To compare the times, they computed (new Website design time - old website design time). The results follow. What is the value of the calculated test statistic?

An investigation of the effectiveness of a training program to improve customer relationships Included a pre-training and post-training customer survey. To compare the differences, they Computed (post-training survey score - pre-training survey score). Seven customers were randomly Selected and completed both surveys. The results follow: For a 0.05 significance level, determine the critical value and the calculated value of the test Statistic?

Married women are more often than not working outside the home on at least a part-time basis, as Do most mannered men. Does a husband's employment status affect his wife's well-being? In an Attempt to answer this question, 75 married female professionals were surveyed as to their job Satisfaction. In this sample, 45 husbands were employed, and 30 were unemployed. The Learning Objective of the study was to compare the mean job satisfaction levels of the married women with Working husbands, with the mean job satisfaction levels of the married women with husbands that Stayed at home. If you were to use Excel's Data Analysis to assist in your solution to this problem, which test would You use?

A national manufacturer of ball bearings is experimenting with two different processes for Producing precision ball bearings. It is important that the diameters be as close as possible to an Industry standard. The output from each process is sampled and the average error from the industry Standard is calculated. The results are presented below: The researcher is interested in determining whether there is evidence that the two processes yield Different average errors. Assume calculated t to be +2.70; what is the decision at the 0.01 level of significance?

A national manufacturer of ball bearings is experimenting with two different processes for Producing precision ball bearings. It is important that the diameters be as close as possible to an Industry standard. The output from each process is sampled and the average error from the industry Standard is calculated. The results are presented below. The researcher is interested in determining whether there is evidence that the two processes yield Different average errors. Ball Bearings Hypothesis Test: Independent Groups (t-test, pooled variance) What is the decision at the 1% level of significance?

A national manufacturer of ball bearings is experimenting with two different processes for Producing precision ball bearings. It is important that the diameters be as close as possible to an Industry standard. The output from each process is sampled and the average error from the industry Standard is calculated. The results are presented below: The researcher is interested in determining whether there is evidence that the two processes yield Different average errors. What is the null hypothesis?