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Hypothesis Testing

Insurance Auditor Hypothesis Testing

An auditor reviewed 25 oral surgery insurance claims from a particular surgical office, determining that the mean out-of-pocket patient billing above the reimbursed amount was $275.66 with a standard deviation of $78.11. (a) At the 5 percent level of significance, does this sample prove a violation of the guideline that the

Hypothesis Testing of Processing Orders

The Web-based company Oh Baby! Gifts has a goal of processing 95 percent of its orders on the same day they are received. If 485 out of the next 500 orders are processed on the same day, would this prove that they are exceeding their goal, using α = .025?

Coin Flip Hypothesis Testing

A coin was flipped 60 times and came up heads 38 times. (a) At the .10 level of significance, is the coin biased toward heads? Show your decision rule and calculations. (b) Calculate a p-value and interpret it.

Hypothesis testing

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 the next year, yielding a sample mean of 14.44 with a standard devi

Applied Statistics on Crash Damages

11.24 In a bumper test, three types of autos were deliberately crashed into a barrier at 5 mph, and the resulting damage (in dollars) was estimated. Five test vehicles of each type were crashed, with the results shown below. Research question: Are the mean crash damages the same for these three vehicles? Goliath Varmint

Statistics

10.30 In Dallas, some fire trucks were painted yellow (instead of red) to heighten their visibility. During a test period, the fleet of red fire trucks made 153,348 runs and had 20 accidents, while the fleet of yellow fire trucks made 135,035 runs and had 4 accidents. At α = .01, did the yellow fire trucks have a significan

Hypothesis Testing and Pension Plan

A sample of employees at a large chemical plant was asked to indicate a preference for one of three pension plans. The results are given in the following table (see attachment). Does it seem that there is a relationship between the pension plan selected and the job classification of the employees? Use the .01 significance level.

Hypothesis Testing - Comparing Miles per Gallon of Gas Types

A research firm wants to compare the miles per gallon of unleaded regular, mid-grade, and super premium gasolines. Because of differences in the performance of different automobiles, seven different automobiles were selected and treated as blocks. Therefore, each brand of gasoline was tested with each type of automobile. The res

Clark Heter is an industrial engineer at Lyons Products. He would like to determine whether there are more units produced on the afternoon shift than on the day shift. A sample of 54 day ...

Clark Heter is an industrial engineer at Lyons Products. He would like to determine whether there are more units produced on the afternoon shift than on the day shift. A sample of 54 day-shift workers showed that the mean number of units produced was 345, with a standard deviation of 21. A sample of 60 afternoon-shift workers sh

Hypothesis Testing - The MacBurger restaurant chain claims that the waiting time of customers for service is normally distributed, with a mean of 3 minutes and a standard deviation of 1 minute. The quality-assurance department found in a sample of 50 customers at the Warren Road MacBurger that the mean waiting time was 2.75 minutes. At the .05 significance level, can we conclude that the mean waiting time is less than 3 minutes?

The MacBurger restaurant chain claims that the waiting time of customers for service is normally distributed, with a mean of 3 minutes and a standard deviation of 1 minute. The quality-assurance department found in a sample of 50 customers at the Warren Road MacBurger that the mean waiting time was 2.75 minutes. At the .05 signi

Medical Blood Plasma. Let x be the variable that represents the pH of the arterial plasma (i.e. acidity of the blood). For healthy adults, the mean of the x distribution is = 7.4. A new drug for arthritis has been developed.

Medical Blood Plasma. Let x be the variable that represents the pH of the arterial plasma (i.e. acidity of the blood). For healthy adults, the mean of the x distribution is = 7.4. A new drug for arthritis has been developed. However it is thought that this drug may change blood pH. A random sample of 31 patients with arthritis

Chrysler Concorde: Acceleration Hypothesis Testing

Consumer reports stated that the mean time for a Chrysler Concorde to go from 0 to 60 miles per hour was 8.7 seconds. a) If you want to set up a statistical test to challenge the claim of 8.7 seconds, what would you use for the null hypothesis? b) The town of Leadville, Colorado has an elevation over 10,000 feet. Suppose you

Applied statistics in business and economics

Prepare answers to the following assignments from the e-text, Applied Statistics in Business and Economics, by Doane and Seward: Chapter 10 - Chapter Exercises 10.30 In Dallas, some fire trucks were painted yellow (instead of red) to heighten their visibility. During a test period, the fleet of red fire trucks made 153,348

Hypothesis test - mean (single small sample) Operating temp.

The mean operating temperature of an aircraft engine during level cruize is supposed to be 190 degrees. An airline tested one particular engine at randomly selected times. The mean temperature on these 25 tests was 193 degrees, with a standard deviation of 3 degrees. Should the pilot worry about th engine running hot? Conduc

Hypothesis Testing - Sugar in Cereals

Sugar in Cereal. Different cereals are randomly selected, and the sugar content (grams of sugar per gram of cereal) is obtained for each cereal, with the results given below for Cheerios, Harmony, Smart Start, Cocoa Puffs, Lucky Charms, Corn Flakes, Fruit Loops, Wheaties, Cap'n Crunch, Frosted Flakes, Apple Jacks, Bran Flakes, S

Hypothesis Testing - Traveling to Outer Space

A CBS News/New York Times poll found that 329 out of 763 adults said they would travel to outer space in their lifetime, given the chance. Estimate the true proportion of adults who would like to travel to outer space with 92% confidence.

Statistics - Hypothesis Testing for Average Credit Card Debt

It has been reported that the average credit card debt for college seniors is $3262. The student senate at a large university feels that their seniors have a debt much less than this, so it conducts a study of 50 randomly selected seniors and finds that the average debt is $2995 with a sample standard deviation of $1100. With a=

Auto Insurance Quotes- Hypothesis Testing Question

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: Does vehicle type vary by mall location?

A student team examined parked cars in four different suburban shopping malls. One hundred vehicles were examined in each location. Research question: At α = .05, does vehicle type vary by mall location? (Data are from a project by MBA students Steve Bennett, Alicia Morais, Steve Olson, and Greg Corda.) Vehicle Type Som

Hypothesis Test for Noise Level in an Airplane Cockpit

High levels of cockpit noise in an aircraft can damage the hearing of pilots who are exposed to this hazard for many hours. A Boeing 727 co-pilot collected 61 noise observations using a handheld sound meter. Noise level is defined as "Low" (under 88 decibels), "Medium" (88 to 91 decibels), or "High" (92 decibels or more). There

Hypothesis Testing for mean

The Rutter Nursery Company packages pine bark in 50-pond bags. From a long history, the packaging department reports that the distribution is normal. At the end of each day Jeff Rutter, the production manager, weighs 10 bags. Below are the weights of the 10 bags from today's production. 45.6 47.7 46.3 47.6 46.2 47.4 55.

Change of Variance in Emergency Room Arrivals

Emergency room arrivals in a large hospital showed the statistics below for 2 months. At σ = .05, has the variance changed? Show all steps clearly, including an illustration of the decision rule. Please use Excel when providing answer.

Hypothesis Testing of Genders Wages

Problem 3: In the population of employee of problem 1, a question was raised on whether male and female above 50 make the same wage. To test this contention, a sample of 25 male and 25 female taken randomly was drawn and the wages found were as follow. Test the Hypothesis that the wages are equal for male and female? Mal

Students t test and hypothesis testing

Please help with the following problem. Provide calculations and explanations. The mean interview time for a standard questionnaire of 31.3 minutes was considered to be excessive so the schedule was revised, yielding a mean interview time for a sample of 40 subjects of 21.3 minutes, with a standard deviation of 1.5 minutes.

Hypothesis Testing

1. Callaway Golf Company's new forged titanium ERC driver has been described as "illegal" because it promises driving distances that exceed the USGA's standard. Golf Digest compared actual driving distances with the ERC driver and a USGA approved driver with a population mean driving distance of 280 yards. Based on nine test