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# Hypothesis Testing

### In spouse murder cases, wife defendants were less likely to be convicted than husband defendants

A U.S. Department of Justice report included the claim that "in spouse murder cases, wife defendants were less likely to be convicted than husband defendants." Sample data consisted of 277 convictions among 318 husband defendants and 155 convictions among 222 wife defendants. Test the stated claim. Assume Aplha = 0.05. What are

### data generated during pre/post treatment surveys

Inspection of student data generated during pre/post treatment surveys shows that among 10 subjects, 7 had higher scores after an experimental treatment, 2 had lower scores, and 1 score did not change. Using the traditional method of hypothesis testing, we need to determine if the experimental course has any effect. Use an alpha

### Normally Distributed Variables and Hypothesis Testing

Assume that the random variable is normally distributed. A courier service advertises that its average delivery time is less than 6 hours for local deliveries. A random sample of times for 12 deliveries to an address across town was recorded. These data are shown here. Is this sufficient evidence to support the courier's adv

### Hypothesis Testing - Mean Diameter of Ball Bearings

A machine that produces ball bearings is set so that the average diameter is .50 inch. A sample of 10 ball bearings was measured with the results shown here. Assuming that the standard deviation is .05 inch, can we conclude at the 5% significance level that the mean diameter is not .50 inch? .48 .50 .49 .52 .53 .48 .49 .47 .

### Answering Hypothesis Testing Questions in Excel

A business student claims that on average an MBA student is required to prepare more than five cases per week. To examine the claim, a statistics professor asks a random sample of ten MBA students to report the number of cases they prepare weekly. The results are exhibited here. Can the professor conclude at the 5% significan

### Hypothesis Testing on Men's Spending Habits

To see if young men ages 9 - 17 spend more or less than the average of \$24.44 per shopping trip, the manager surveyed 33 young men and found the average amount spent was \$22.67. The pop std us \$3.70. At alpha 0.2, can it be concluded the average amount spent by the young men is not equal to \$24.44 Perform appropriate hypoth

### Differences Between Men and Women in Living Situations

A survey by the national institute of health asked a random sample of young adults (aged 19 to 25), "Where do you live now? That is, where do you stay most often?" We earlier compared the proportions of men and women who lived with their parents. Here now is the full two-way table (omitting a few who refused to answer and one w

### Statistical Analysis on Dyes

The color of a fabric depends on the dye used and also how the dye is applied. This matters to clothing manufacturers, who want the color of the fabric to be just right. The study discussed in the previous exercise went on to dye fabric made of ramie with the same "procion blue" dye applied in two different ways. Here are the

### Publishing Papers

Publishing scientific papers online is fast, and the papers can be long. Publishing in a paper journal means that the paper will live forever in libraries. The British Medical Journal combines the two: it prints short and readable versions, with longer versions available online. Is this OK with authors? The journal asked a r

### Statistical Analysis: Running Red Lights

A random digit dialing telephone survey of 880 drivers asked, "Recalling the last ten traffic lights you drove through, how many of them were red when you entered the intersectinos?" Of the 880 respondents, 171 admitted that at least one light had been red. a)Give a 95% confidence interval for the proportion of all drivers who

### Fatal Accidents Statistical Analysis

As part of a study on transportation safety, the U.S. Department of Transportation collected data on the number of fatal accidents per 1000 licenses and the percentage of licensed drivers under the age of 21 in a sample of 42 cities. Data collected over a one-year period follow. Please see the attached file for the table.

### Test for Differences: Types of Browsers

In a study conducted to investigate browsing activity by shoppers, each shopper was initially classified as a nonbrowser, light browser, or heavy browser. For each shopper, the study obtained a measure to determine how comfortable the shopper was in a store. Higher scores indicate greater comfort. Suppose the following date we

### Hypothesis Testing: Positive or Negative Relationships

1. A researcher demonstrated a correlation of r = 0.60 between teacher attire and student academic performance across 150 grade schools in her state. She concluded that encouraging teachers to be properly attired will increase academic performance. Do you agree or disagree with her conclusion? Why? 2. Give three real life or

### Hypothesis Testing

Assume that a hypothesis test of the given claim will be conducted. The college Dean of Admissions claims that the times students require to earn a bachelors degree have a mean less than five years. Which equality/inequality (e.g., =, =<, etc.) would use in the Alternative Hypothesis?

### Hypothesis Testing

Assume that a hypothesis test of the given claim will be conducted. The college Dean of Admissions claims that the times students require to earn a bachelors degree have a mean less than five years. Which equality/inequality (e.g., =, =<, etc.) would use in the Null Hypothesis?

### Hypothesis testing : Proportion

It has been reported that 80% of taxpayers who are audited by the IRS end up paying more money in taxes. Assume that the auditors are randomly assigned cases and that one of the ways the IRS oversees its auditors is to monitor the percentage of cases that result in the tax payer paying more in taxes. A sample of 400 cases handl

### Statistical IQ Testing of Employees

Please explain the answers. Descriptions are in the file. 3. In order to test whether the mean IQ of employees in an organization is greater than 100, a sample of 35 employees is taken and the sample value of the computed test statistic, t_ = 3:5 The null and alternative hypotheses are: A) H0: X = 100; Ha: X 6= 100. B) H0:

### Test Findings: sample of difference in wages based on gender

The wages data set has a sample size of 100 people that were surveyed. Our error margin was .05. For the 47 females surveyed the mean wage was \$24,451 per year with a standard deviation of \$12,455 per year. For the 53 males surveyed the mean wage was \$36,492 per year with a standard deviation of \$18,447 per year. Check the clai

### Statistics - Hypothesis Testing Adjustment

Discuss the link between the estimate and the parameter in the context of an hypothesis test. Be sure to reference the appropriate steps of the five step process in your response, based on the steps below: Step 1: State null and alternate hypothesis. Step 2: Select a level of significance Step 3: Identify the test statisti

### Testing of hypothesis problems

Dear OTA, Can you please help me with this homework assignment? Thanks 1. Burney Watt, chief electrician for the Prescott Electrical Coop has been watching the electric bills for 10 properties in Prescottvilla, the up and coming snobby subdivision south of town. The residents there have been complaining that their "b

### 1. The General Social Survey is an annual survey given to about 1,500 U.S. adults selected at random. 2. The university data center has two main computers. The center wants to examine whether computer 1 is receiving ... [See the attached questions file.]

1. The General Social Survey is an annual survey given to about 1,500 U.S. adults selected at random. Each year, the survey contains several questions meant to probe respondents' views of employment. A recent survey contained the question "How important to your life is having a fulfilling job?" Of the 261 college graduates surve

### Regression Analysis of Wine Consumption

Please see the attached file. **All work shown (step by step), in simple terms please!!! No excel, just formulas**. 20) A marketing research firm wished to study the relationship between wine consumption and whether a person likes to watch professional tennis on television. One hundred randomly selected people are as

### Significance level and p-value

A large department store hired a researcher to compare the average purchase amounts for the downtown store with that of its mall store.  The information shown was obtained.  At the 0.01 significance level can it be concluded that the mean amount spent at the mall store is larger?Estimate the p-value? Average purchase amount

### Hypothesis Testing using ANOVA

Scrap rates per thousand (parts whose defects cannot be reworked) are compared for 5 randomly selected days at three plants. Does the data prove a significant difference in mean scrap rates? ScrapRate Plant A Plant B Plant C 11.4 11.1 10.2 12.5 14.1 9.5 10.1 16.8 9.0 13.8 13.2 13.3 13.7 14.6 5.9.

### P-value equality of mean

Do a two-sample test for equality of means assuming equal variances. Calculate the p-value. a. Comparison of GPA for randomly chosen college juniors and seniors: ¯x1 = 3.05, s1 = .20, n1 = 15, ¯x2 = 3.25, s2 = .30, n2 = 15, &#945; = .025, left-tailed test. b. Comparison of average commute miles for randomly chosen stude

### Chi-Statistic in Hypothesis Testing

A machine used for packaging seedless golden raisins is set so that their standard deviation in the weight of raisins packaged per box is 0.25 ounce. The operations manager wishes to test the machine setting and selects a sample of 30 consecutive raisin packages filled during the production process. Their weights are as record

See attachment for problem A student team examined parked cars in four different suburban shopping malls. One hundred vehicles were examined in each location. Research question: A

### Do average calls per week differ from district to district?

1. Using the data file TRX.XLS (attached), construct a 95% confidence interval for the average number of prescriptions written for Prilosec. Assume the distribution in normally distributed. There are 24 months to be averaged. Use Descriptive Statistics in Excel and be sure to check the appropriate options. If you can't see the o

### Hypothesis Testing

A lumber company has claimed that the standard deviation for the lengths of their 6 foot boards is 0.5 inches or less. To test their claim , a random sample of 17 six-foot boards is selected; and it is determined that the standard deviation of the sample is 0.42. Do the results of the sample support the company's claim? Use alph

### Description of Statistics - Hypothesis Testing

1. Consider the following hypothesis test: Ho: u</= 12 Ha: u>12 A sample of 25 provided a sample mean x=14 and a sample standard deviation s = 4.32 a. Compute the test statistic. b. Use the t distribution table to compute a range for the p value c. At alpha= 0.05, what is the conclusion. d. What is the rejection rule us