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# Hypothesis Testing

### Sample and Significance Level

The president of the American Insurance Institute wants to compare the yearly costs of auto insurance offered by two leading companies. He selects a sample of 15 families, some with only a single insured driver, others with several teenage drivers, and pays each family a stipend to contact the two companies and ask for a price q

### Statistics: Frequency, Chi-Square, Mean Square, and Error

Use the following information to answer questions: A manufacturer of automobile transmissions uses three different processes. The management ordered a study of the production costs to see if there is a difference among the three processes. A summary of the findings is shown below. Process 1 Process 2 Process 3 Total Proce

### Critical value, level of risk

1. (10) The CEO for the Red White and Blue T-Shirt Company expects quality garments produced with a minimum of defective garments. Further, he expects the same quality work from his employees regardless of whether they work in the day or in the evening. To test productivity quickly, he has his shift foremen record the number

### Jerry's Bargain Department Store: Level of Risk

Jerry's Bargain Department Store spent \$50,000 on a training program to improve sales effectiveness of its employees. Below is a table of the before and after sales amounts for a random sample of employees who took the training program. Assume that data is recorded for an equal period of "before"-"after" time. Use the 1% level f

### A Knowledge about Hypothesis Test

A consumer watchdog organization wants to see whether Bank N in the northern part of a state has a higher default rate than Bank S in the southern part of that same state. Researchers for the group sample the proportion of defaults on loans at both banks. Out of 100 loans for Bank N, they find 30 have defaulted; out of 100 lo

### Statistics - Null & Alternative Hypothesis - Critical Values

Identifying H0and Hr in ex 5-12 , examine the given statement , then express the null hypothesis H0 and alternative hypothesis H1 in symbolic form. 6. The mean IQ of statistics students is at least 110. 8. The percentage of men who watch golf on tv is not 70%, as is claimed by the Madison Advertising Company. Finding C

### Mean

1) Recall that "very satisfied" customers game system a rating that is at least 42. Suppose that the manufacturer of the XYZ- box wishes to use the 65 satisfaction ratings to provide evidence supporting the claim that the mean composite satisfaction rating for the XYZ=box exceeds 42. a) letting µ represent the mean composit

### In testing the equality of the two means below, what is the test statistic? (Use the unequal variances formula)

In testing the equality of the two means below, what is the test statistic? (Use the unequal variances formula) Sample 1 Sample 2 Sample size 9 12 Sample mean 80 115 Sample variance 550

### Multiple choice questions from hypothesis testing.

Many elementary school students in a school district currently have ear infections. A random sample of children in two different schools found that 16 of 42 at one school and 21 of 36 at the other had this infection. At the .05 level of significance, is there sufficient evidence to conclude that a difference exists between the

### Left-Tailed Test

Using the z table in Table E of Appendix C, determine the critical value for the left-tailed test with a = 0.02. A) 2.05 B) - 2.33 C) - 2.05 D) 2.33

### Difference Between Testing a Single Mean or Two Means

Explain the difference between testing a single mean and testing the difference between two means. What two assumptions must be met when one is using z test to test differences between two means? When can the sample standard deviations s1 and s2 be used in place of the population standard deviations σ1 and σ2 ?

### Hypothesis Testing, Significance Levels, Critical Values and Decision Rule

Please see the attached file for the fully formatted problems. Faced with rising fax costs, a firm issued a guideline that transmissions of 10 pages or more should be sent by 2-day mail instead. Exceptions are allowed, but they want the average to be 10 or below. The firm examined 35 randomly chosen fax transmissions during t

### 1 Tailed vs 2 Tailed Test and Null vs Alternative Hypothesis

1. Explain the difference between a left-tailed, two-tailed, and right-tailed test. When would we choose a two-tailed test? How can we tell the direction of the test by looking at a pair of hypothesis? How can we tell which direction (or no direction) to make the hypothesis by looking at the problem statement (research questio

### Hypothesis Development and Five Step Hypothesis Testing

The hypothesis should be developed to include an assessment of women with similar education and work experiences earn less money than men with similar qualifications. The data set and legend are included as an attachment. Please provide a five-step hypothesis test with the data relevant to the selection (data set and legend

### The Significance Level and Estimate P-Value

"A recent article in The Wall Street Journal reported that the 30-year mortgage rate is now less than 6 percent. A sample of eight small banks in the Midwest revealed the following 30-year rates (in percent): " 4.8 5.3 6.5 4.8 6.1 5.8 6.2 5.6 At the .01 significance level, can we concl

### Equal Variances Formula: Determining Test Statistic Example

In testing the equality of the two means below, what is the test statistic? (Use the equal variances formula). Sample 1 Sample 2 Sample size 12 8 Sample mean 115 80 Sample variance 700 450 A) 0.28 B) 3.27 C) 2.37 D) 0.1

### Test Value

A pharmaceutical company is testing the effectiveness of a new drug for lowering cholesterol. As part of this trial, they wish to determine whether there is a difference between the effectiveness for women and for men. At = .05, what is the test value? Women Men Sample size 40 70 Mean effect 7 6.75 Sample varianc

### Statistics - Difference between 1 tailed and 2 tailed test

Explain the difference, if any, between a 1-tailed test and a 2-tailed test.

### Hypothesis Testing on Multiple Scenarios

Problem 1 Consider the Mission Valley Power Company (MVP), which has over 6000 customers. In response to a request from the Michigan Public Utilities Commission, MVP needs to estimate the average kilowatts of electricity used by customers on April 1. The only way to get this number is to select a random sample of customers and

### Descriptive Statistics (Comparing Variation in Two Samples)

Comparing ages of a Marathon Runners: Use a 0.05 significance level to test the claim that for the runners in the New York City marathon, men and women have ages with different amounts of variation.

### Descriptive Statistics (Comparing Variation in Two Samples)

Tobacco and Alcohol Use in Animated Children's Movies: Lists times (in seconds) that animated children's movies show tobacco use and alcohol use. The 50 times of tobacco use have a mean of 57.4 sec and a standard deviation of 104.0 sec. the 50 times of alcohol use have a mean of 32.46 sec and a standard deviation of 66.3 sec.

### Standard Deviation for Nielsen Media Research

PROBLEM SET II ALTERNATE 1 9-11. The owner of Britten's Egg Farm wants to estimate the mean number of eggs laid per chicken. A sample of 20 chickens shows they laid an average of 20 eggs per month with a standard deviation of 2 eggs per month. a. What is the value of the population mean? What is the best estimate of this v

### Standard Deviation of Breakfast Cost

A recent survey indicated that the average amount spent for breakfast by business managers was \$7.58 with a standard deviation of \$0.42. It was felt that breakfasts on the West Coast were higher than \$7.58. A sample of 81 business managers on the West Coast had an average breakfast cost of \$7.65. At a= 0.05, what is the t

### Z table

Using the z table in Table E of Appendix C, what are the critical values for a two-tailed test when a=0.03. A) ± 2.17 B) ± 2.05 C) ± 2.33 D) ± 1.88

### Telephone Efficiency Significance

To encourage telephone efficiency, a catalog call center issues a guideline that at least half of all telephone orders should be completed within 2 minutes. Subsequently, a random sample of 64 telephone calls showed that 40 calls lasted over 2 minutes. (a) At α = .05 is this a significant departure from the guideline in

### Hypothesis testing for population proportion problems

A study by the Investment Company Institution (ICI) in 2004, which randomly surveyed 3,500 households and drew upon information from the IRS. If found that 72% of households have conducted at least one IRA rollover from a an employer sponsored retirement plan. Suppose a recent random sample of 90 households in the greater Detr

### Hypothesis Testing of Genetically Modified Foods

Design (but not do) a test to see if genetically modified foods are different from non-genetically modified (NGM) foods. Assume you are designing a study that will analyze GM and NGM foods, and answer the following questions. 1. What will your null and alternative hypotheses be? (Hint: Ensure your null and alternative hypo

### Certainty independent of credits earned

15.18 Sixty-four students in an introductory college economics class were asked how many credits they had earned in college, and how certain they were about their choice of major. Research question: At α = .01, is the degree of certainty independent of credits earned? Certainty Credits Earned Very Uncertain Somewhat Certai

### Nonparametric Hypothesis Test

Using the research question and data below conduct a equivalent nonparametric test of hypothesis below. The hypothesis for the ANOVA test is: H0: &#956;1=&#956;2=&#956;3=&#956;4=&#956;5=&#956;6=&#956;7=&#956;8=&#956;9 (all means are equal) H1: Not all means are equal (at least one is different) Telecommunication Servi

### Hypothesis of Right-Tailed Test and Significance

In Utica, Michigan, 205 of 226 school buses passed the annual safety inspection. In Detroit, Michigan, only 151 of 296 buses passed the inspection. (a) State the hypotheses for a right-tailed test. (b) Obtain a test statistic and p-value. (c) Is normality assured? (d) If significant, is the difference also large enough to be