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Hypothesis Testing

Using proportional relationships.

Assume that male snakes of a particular species are all scaled versions of the same basic shape. (i) (a) Describe in words the sort of relationship that you might expect there to be between the volume and the length of a snake. What relationship would you expect there to be between the mass and the length of a snake ?.

Formula

A. (Ey)(Ex2)-(Ex)(Exy) / n(Ex2) - (Ex2) B. n(Exy) - (Ex)(Ey) / square root of n(Ex2) - (Ex)2 C. r= n(Exy) - (Ex)(Ey) / sq. root of [n(Ex2) - (Ex)2][n(Ey2) - (Ey)2

Hypothesis testing

21st Century Insurance Company claims that telephone calls for policy holder information are answered in at most 3 minutes. A random survey of 36 phone calls results in the mean 3.3311 and standard deviation 2.1788. Is there sufficient evidence to disprove their claim? Alpha .05

Average, Standard Deviation, Confidence Interval, Test of Hypothesis

A vendor supplies refreshments at a baseball stadium and must plan for the possibility of a World Series contest. In the accompanying table, x represents the number of games required to complete a World Series contest. P(x) is the probability that x games are required to complete the contest. x P(x) 4

Statistics Cases

A) What is the response variable and what is the factor? b) Ho many levels of the factor are being studied? c) Is there any difference in the average time to failure of the disks from the 3 different suppliers? If so, which ones are different? d) What is your recommendation to the company and why?

Diaper Hypothesis - Statistics

14.1 A diaper company is considering 3 different filler materials for their disposable diapers. Eight diapers were tested with each of the 3 filler materials and 24 toddlers were randomly given a diaper to wear. As the child played, fluid was injected into the diaper every 10 minutes until the product failed (leaked). The amount

Statistics

12.17 M&M / Mars claims that at least 20% of the M&M's in each package are the new blue color. Set up the null and alternative hypotheses to test this claim. 12.21 An automobile company thinks that with new designs, its cars will last longer before having a problem. For this reason, the company wishes to extend the warranty

Tests of hypothesis: difference between means,

13.11 Top Ten Business Computability PC Connection Software Packages Price ($) Price ($) Windows 95 Upgrade 88 95 Norton Anti-Virus 59 70 McAfee ViruScan 49 60 First Aid 97 Deluxe 54 58 Clean Sweep III 37 37 Norton Utilities 68 75 Netscape Navigator 45 40 MS Office Pro 9

Explanation to "Test of hypothesis" question

10.10 In an attempt to improve quality many manufacturers are developing partnerships with their suppliers. A local fast-food burger outfit has partnered with its supplier of potatoes. The burger outfit buys potatoes in bags that weigh 20 lbs. It wishes to set up the null and alternative hypotheses to test if the bags do weigh

Z Scores and Percentiles

Z Scores and Percentiles Mary is a social worker who leads a treatment group of young adults diagnosed with chronic anxiety. Group members are selected for treatment based on their scores on a particular screening device, Anxiety Scale A. This instrument has a mean of 60 and a standard deviation of 12. Those scoring over 72

Sampling and hypothesis testing: test statistic, average length, preacher's sermons, stratified random sample, judgment sample, sample size, type of error, probability, proportion, confidence interval

1) A woman and her son are debating about the average length of a preacher's sermons on Sunday morning. Despite the mother's arguments, the son thinks that the sermons are more than twenty minutes. For one year, he has randomly selected 12 Sundays and found an average time of 26.42 minutes with a standard deviation of 6.69 min

Hypothesis

The quality-control manager at a lightbulb factory needs to determine whether the mean life of a large shipment of lightbulbs is equal to the specified value of 375 hours. The process standard deviation is known to be 100 hours. A random sample of 64 lightbulbs indicates a sample mean life of 350 hours a. State the null and alt

Hypothesis Testing Question

School A states the average number of days missed by each student is 4.0. Office personnel randomly sampled a portion of their attendance records to determine if this claim was accurate. For the previous year, the following data was obtained from the sample group, regarding absences for that year: 4, 4, 3, 2, 6, 8, 7, 1, 9, 3, 1

Hypothesis Testing - Compute the statistical test using the z test

A sample of 40 observations is selected from one somewhat normal population. The sample mean is 102 and the sample standard deviation is 5. A sample of 50 observations is selected from a second source. The sample mean was 99 and the standard deviation was 6. Conduct a test of the hypothesis using the .04 level of significance.

statistical test using the z test and the null

A sample of 40 households with school-age children in Middletown was randomly selected. The mean length of time was 7.6 years, with a standard deviation of 2.3 years. A sample of 55 households in Brockton revealed the mean length of time was 8.1 years, with a standard deviation of 2.9 years. At the .05 level of significance, can

Neyman-Pearson Significance Testing: Critical Regions

What I'm looking at immediately is "Using the .05 cutoff figure, find an appropriate critical region for testing the null hypothesis 'theta is greater than or equal to .154 against the alternate hypothesis 'theta is less than .154' and provide a Neyman-Pearson analysis.". Background facts for the problem: In the county, 1

Standard error of proportion, Error

Nationally the proportion of American households with income above $100,000 is 10%. A researcher in State of California finds that out of a sample of 300 households , 35 have income above $ 100,000. Can it be concluded from this sample that the proportion of households in california with income of $100,000 exceeds the proportion

Hypothesis Testing for a Retail Store Manager

Problem 1 A retail store manager is trying to estimate the average purchase transaction amount for a particular store. She takes a sample of 35 transactions and determines the mean purchase transaction amount from this same is $85 with a standard deviation of $35. a) What is the point estimate of the average purchase tran

Inference

Various types of retail outlets sell toys during the holiday season. Among them are specialty toy stores, the large discount toy stores, and other retailers that carry toys as only one part of their stock of goods. Is there any difference in the dollar amount of a customer purchase between a large discount toy store and a spec

Testing a hypothesis.

The normal serum hemocrit level is 0.41 milligrams to 100 milligrams of blood. The level in elderly patients is significantly low at 0.31. 25 patients out of 100 are normal levels. The standard deviation is 0.6. A medication that is designed to increase the hemocrit is taken in 100 patients for one month. A testing is foun

Test hypotheses

PERSISTANT LOW HEMOCRIT IN ALL THE ELDERLY PATIENTS IN A NURSING HOME F .31, WITH A NORMAL OF .41. AN INTERVENTION PROGRAM OF AN IRON SUPPLEMENT WAS INITIATED TO SEE IF THE HEMOCRIT WOULD INCREASE. A RANDOM SAMPLE OF 100 PATIENTS SHOWED THAT 60 PATIENTS NOW HAD ELEVATED LEVELS OF HEMOCRIT OF .41. CAN WE CONCLUDE AT ALPHA= 0.0

Confidence Intervals

Use these data and hypothesis-testing techniques along with a 5% level of significance to determine whether the mean hourly wage of a manufacturing worker has changed.

Hypotheses Testing

A MANUFACTURER OF COMPUTER CHIPS CLAIMS THAT MORE THAN 90% OF HIS PRODUCTS CONFORM TO SPECIFICATIONS. IN A RANDOM SAMPLE OF 1000 CHIPS DRAWN FROM A LARGE PRODUCTION RUN, 875 WERE ACCEPTABLE. DO THE DATA PROVIDE SUFFICIENT EVIDENCE AT THE 1% LEVEL OF SIGNIFICANCE TO CONCLUDE THE MANUFACTURER'S CLAIM IS FALSE? a. State the Null

Hypothesis Testing for Samples

Hypothesis testing: Please help me with the sample problem 1 (two attachments, page 2 and 3). If you have trouble with the attachments, you can download them here: http://www.sunflowerlabs.com/samples/c2fecd130002.GIF http://www.sunflowerlabs.com/samples/c2fecd130003.GIF

Stats tests

I am looking for the appropriate statistical test(s) to run on some data. I am trying to find out whether there is any significant differences in 2 groups of people (full-time workers and part-time workers) who all took a customer service survey. The survey scores the person on 8 subscales of customer service, plus on

Formulating a hypothesis and classifying the type of error.

A manufacturer of stereo systems has a production line that produces an average of 100 stereo systems per day. Because of new government regulations, a new safety device has been installed, which the manufacturer believes will reduce average daily output. A sample of 49 days output after the installation of the safety device y

Testing a claim using a mean weight, standard deviation and confidence levels.

A vendor sells turkeys to a restaurant chain. He claims that the mean weight of the turkeys is more than 15 pounds. A sample of 16 turkeys yields a mean of weight of 14 pounds and a standard deviation of 4 pounds. At a significance level of 0.05 shall we reject the vendor's claim? Set up the Hypothesis test in "standard form" an

Working with hypothesis tests.

If when you do a Hypothesis test about the Population Mean, somehow you have the actual value for the Population Standard Deviation. Suppose that you were able to get a sample of size 100, and did not know the Population Standard Deviation. What can you do to still carry out the Hypothesis test?

Understanding the types of a hypothesis test.

A Hot Fudge Sundae has on average 12 ounces of ice cream. If I were to set up a hypothesis test to test the ability of a new employee making the hot fudge sundae with an average of 12 ounces of ice cream, would the hypothesis test be a "one tailed" or a "two tailed" test? Briefly Explain.

Testing a claim in regards to a mean weight using a confidence level.

A flour manufacturer packs flour into paper bags, each of which is supposed to hold 10 pounds, or 160 ounces. Some customers have complained that the bags hold only 9.5 pounds, or 152 ounces. A test is conducted to determine whether the complaint is warranted. The weight of each bag is normally distributed with a Population Stan