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Hypothesis Testing

How to test hypotheses of population mean

Subject: Null/alt hypoth; decision rule; value of test stat; Ho and p-value, interpret Details: The manufacturer of the X-15 steel belted radial truck tire claims that the mean mileage the tire can be driven before the treads wear out is 60,000 miles. The standard dev of the mileage is 5,000 miles. The C Truck Company bought 4

Analyze the data.

Pearl(1968)reports lactation studies with ewes.In one of his experiments nine ewes were divided into groups of three.In group 1 the ewes and lambs were fed freely during the lactation period;in the other groups two different methods of restricting the food intake were used.He records the yields of residual milk in grams for each

Random sampling

A quality inspector is interested in the time spent replacing defective parts in one of the company's products. The average time spent should be at most 20 minutes per day according to company standards. To conduct the test, a random sample of 36 employees is chosen. The average time spent replacing defective parts for the


Details: 1. What is the between a raw score of 113 and 126 in a normal distribution with a mean of 100 and a standard deviation of 10? Find the area below and under the score of 135. 2. Test null hypothesis that urban and rural residents both have the same attitude toward gun control(data1). Group 1 is a group of the urban r

Solutions to six separate problems 1. Sample size calculation when estimating the mean of a normal distribution 2. Small sample hypothesis test for a population mean 3. Small sample hypothesis test for the difference of two population means 4. Hypothesis test for a population proportion 5. Small sample hypothesis test for a population mean 6. Hypothesis test for a population proportion

1.) In a normal distribution with mean 59 and standard deviation 22, how large a sample must be taken so that there will be at least a 90 percent chance that its mean is greater than 53? 2.) In the second week of June 1996, the average number of units produced per week for all models of automobiles manufactured in the U.S. w


We know that the Gamma value=0.298 and the approxiamte p-value=.000 which is understood p-value<=0.001. So, under a significance level alpha=0.001, we should reject the null hypothesis, ie., there is a significance difference between the groups


Standards set by the FDA indicate that Americans should not exceed an average daily sodium intake of 3300 milligrams (mg). To find out whether Americans are exceeding this limit a sample of 25 Americans is selected and the mean daily sodium intake is found to be 3120 mg with a standard deviation of 800 mg. Is this sufficient to

Confidence Limits

Recall that the SAT math test has a theoretical mean of 500 and a standard deviation of 100: Suppose a sample of 50 mathematically -gifted youngsters scored a mean of 560 on the SAT math test. What would the 90 percent confidence limits be? What would the 99 percent confidence limits be for the same sample?

Decision criteria

Larry Jacava is considering producing a novelty item for golfers that will be sold through pro shops. Larry has decided on a selling price of $3.50 for the item. The item's variable cost of production is $2.00 per unit with a fixed cost of $3,750. Larry has marketed his production to local pro shops and believes the demand for t

Degrees of freedom, value of the test statistic, null hypotheses

The daily production rates of a sample of sixteen workers in a factory before and after a training program (which was shown to be effective in other plants provided the following results: Use alpha equal to .01 Mean of the difference scores 5 Standard deviation of the difference scores =8 Is this problem, one tail, two tai

Test of Hypothesis for difference in proportions: A random sample of 200 workers from Factory A showed that 130 were satisfied with their job. Another random sample of 125 workers from Factory B showed that 70 were satisfied with their job. Can it be concluded that the proportion of satisfied workers in Factory A is greater than in Factory B?

A random sample of 200 workers from Factory A showed that 130 were satisfied with their job. Another random sample of 125 workers from Factory B showed that 70 were satisfied with their job. Can it be concluded that the proportion of satisfied workers in Factory A is greater than in Factory B? Formulate and test the appropriate

Hypothesis testing: Sample Size

A market research agency would like to estimate the proportion of Canadian households owning a personal computer. What minimum sample size will be required if they want to be 99% confident that the sample proportion will not differ from the true population proportion by more than 5%?

Give the null and alternative hypothesis for the test. If you wish your probability to be of (erroneously) deciding that mu>30, when in fact =30, to equal 0.05, what is the value of alpha for the test?

1) A random sample n=40 observations from a population produced a mean of 30.9 and a standard deviation of 2.4. Suppose that you wish to show that the population mean (mu) exceeds 30. A) Give the null and alternative hypothesis for the test. B) If you wish your probability to be of (erroneously) deciding that mu>30, when i

Hypothesis Testing

In one of the ethnically diverse areas of a large city, a branch manager of a local bank has been receiving complaints from the clients about staff behavior. He has decided to introduce a training program for his staff, and has retained the services of a human resources consultant. Over a weekend, the consultant has invited repr

To be solved by SAS

A researcher wants to investigate the null hypothesis: Ho : µ1= µ2 = µ3 = µ4 using &#945; = 0.05. Given &#963;²= 1 and &#931; &#945; j² = 2.76, how many subjects j should be assigned to each treatment for power, &#960; = 1 - &#946; ~ .80

Data Analysis : Null Hypotheses and Normal Distribution

A random sample of 8 petrol stations in each of three European countries A, B and C was taken. The price per litre at each station was recorded in Euros. The prices are given below. A 7.80 8.00 7.98 8.20 8.00 7.99 8.10 7.90 B 8.01 7.75 8.00 7.77 8.01 8.01 8.12 8.20 C 8.10 7.92 8.01 7.88 8.30 8.22 8.56 8.10 Discuss wa

Inferential statistics used in hypothesis tests

What inferential statistic would you choose to test the following hypotheses? Briefly explain your answers. There is a positive relationship between the patient's rating of pain using the Visual Analog scale and the amount of drug administered to the patient. The annual income among male and female nurses differs signifi

Psychology Statistics 240

A social psychology graduate student hypothesizes that taller women tend to date taller men, and that shorter women tend to date shorter men. To test this hypothesis, she visits a dance club just off campus and interviews the first 10 couples she meets, measuring (to the nearest centimeter) the heights of the men (X) and the he

At a 0.05 level of significance, can you justify the Deputy's claim that the average salary of a public sector manager is lower than that of his or her counterpart in the private sector?

Public service managers complain that their salaries are falling behind those of their counterparts in the private sector. To make a strong case for his employees, the Deputy Minister of Finance has produced a document for the Minister's consideration. The document compares the average salary of ten highly placed managers with t

Hypothesis Testing for difference between means. The task force claims that the average cost per visit will be significantly less if the suggestion is adopted. At a 0.05 level of significance, test the claim of the task force.

Because of massive cutbacks in transfer payments to the provinces, provincial governments are in a quandary over how to maintain a high standard in health care. Given the sensitive nature of the issue, the provinces have set up independant commissions to study the issue. A task force in Alberta has suggested that more "community

Hypothesis testing is embedded.

The "Mars" division of a big auotmobile manufacturer specializes in manufacturing scooters for export. The company claims that these scooters average at least 55 miles per gallon in city driving. An independant consumer avocate road tested a sample of 25 scooters. The sample showed an average of 60 miles per gallon, with a stand

Hypothesis in statistics, problem

A cereal manufacturer sells boxes of cereal that list the weight as 19 oz. A random sample of 60 boxes was taken, with the contents carefully weighed. Assume a mean weight of (random variable?) x = 19.9 oz. and a standard deviation of s = 0.67 oz. resulted from the sample data. would this idicate that the actual mean weight,u of

Statistic problem- hypothesis

A nectarine-packing firm claims that the nectarines they ship have a mean weight of 5.22 ounces. A test on n = 10 randomly selected nectarines, gave the following results, in ounces: 5.94 5.15 5.73 6.31 5.63 5.04 5.10 5.03 5.13 5.21 Do the data indicated that the actual mean weight is less than the mean weight claimed by t

Perform a Z -test on a 52 sample class

Please see the paper enclosed. Perform a Z -test on a 52 sample class (26 samples in the paper + 26 samples in the 2nd attachment), and determine the p-value to validate the conclusion (decision). Please perform all the calculations similar to how it was done in the paper meaning not just giving me the result number but show

Significance Level: Fairfield Homes

Fairfield Homes is developing two parcels near Pigeon Fork, Tennessee. In order to test different advertising approaches, they use different media to reach potential buyers. The mean annual family income for 75 people making inquiries at the first development is $150,000, with a standard deviation of $40,000. A corresponding sam