A firm specializing in the preparation of income tax returns, claims the mean refund for customers who received refunds last year was R150. For a random sample of 12 customers who received refunds last year, the mean amount was found to be R125, with a standard deviation of R43. What is the alternative hypothesis?

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A: Given that, Mean= 91 Standard deviation, sigma= 21 Sample size, n=20 Hypothesis,  Ho:  the agent’s…

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A: Answer: X ~ Normal distribution X~ N (μ, σ) The given values are Mean = μ = 40 Standard deviation= σ…

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A: From the provided information, Sample size (n) = 137 Sample mean (x̅) = 502 Population standard…

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A:

Q: The standard deviation may not be greater than the mean. O True O False

A: False: standard deviations may be greater than mean  example: random variable x follow standard…

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A: From the provided information, Mean (µ) = 120.1 mmHg Standard deviation (σ) = 15.1 mmHg X~N (120.1,…

Q: Realtor Elaine Snyderman took a random sample of 12 homes in a prestigious suburb of Chicago and…

A: Given, Null Hypothesis(H0): μ = 825000 Alternate Hypothesis(Ha) : μ < 825000 α = 0.05 x¯ = 780000…

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A: given: Mean=$7000 SD=$1500

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A: It is given that the mean is 72000 and the standard deviation is 3000.

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A: The mean is 26 and the standard deviation 3.0.

Q: A tire manufacturer claims (based on years of experience with tires) that the mean mileage is…

A: Given: n= 101.0 ,x̄= 31000.0 ,s= 5000.0 µ= 35000.0 ,significance level(∝)= 0.02Now here using…

Q: What is the standard deviation for the following set of N= 5 scores: 10, 10, 10, 10, and 10? (Note:…

A: Given data 10,10,10,10,10and N = 5Mean (μ) :  10+10+10+10+105μ = 505=10

Q: A shareholders' group, in lodging a protest, claimed that the mean tenure for a chief executive…

A: Given information- Population mean, μ = 9 years Sample size, n = 95 Significance level, α = 0.01…

Q: The mean and standard deviation of the sampling distribution of the mean is shown as?

A:

Q: A recent Gallop Poll indicates that 80 % of voting age adults disapprove of Congress. If 700 voting…

A: Let p be the probability that a voting age adult disapproves of Congress. Given that p = 0.80 Let X…

Q: A chemical engineer claims that the average daily yield of a chemical manufactured in a chemical…

A: The standard error is,

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A: Denote μ as the population mean income of families living within two miles of proposed building…

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A:

Q: n their website, a property management company states that the mean monthly rent for apartments on…

A: Given: Population meanμ=675Sample size(n)=20Sample standard deviation(s)=21

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A: Let X be the golf scores. It is given that X is normally distributed with mean 68 and standard…

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A:

Q: A tool company claims that the mean number of defective screws they produce per box is 72. The mean…

A:

Q: the standard error of the mean for a random sample of 49 tax returns is ________.

A: Given information Mean = $ 1,949 Standard deviation = $750 Sample size = 49

Q: Suppose that the scores on a statewide standardized test are normally distributed with a mean of 67…

A: From the provided information, Mean (µ) = 67 Standard deviation (σ) = 6 Let X be a random variable…

Q: The department has decided that all marks from introductory psychology courses should be reported…

A: Here For two different  Distribution Comparison we will Use Standardized statics (Z)..

Q: If the weekly grocery expenditure of households in a certain urban market is known to be normally…

A:

Q: In an intelligence exam to determine the IQ of students, it is found out that the results are…

A: Let X be the IQ score of students which follows normal distribution with mean 100 and standard…

Q: Three years ago, the mean price of an existing single-family home was $243,761. A real state broker…

A: Given H0: μ=243,761 H1: μ<243,761

Q: In a mid-size company, the distribution of the number of phone calls answered each day by each of…

A: Given Information: Mean μ=48 Standard deviation σ=7 Using empirical rule, to find the approximate…

Q: A retailer believes that its new advertising strategy will increase sales. Previously, the mean…

A: Given that A retailer believes that its new advertising strategy will increase sales. Previously,…

Q: In a mid-size company, the distribution of the number of phone calls answered each day by each of…

A: The independent variable is receptionists. The random variable is number of phone calls answered…

Q: What is the z-score of a value of 27, given a set mean of 24, and a standard deviation of 2?

A:

Q: A chemical engineer claims that the average daily yield of a chemical manufactured in a chemical…

A: Introduction:The null hypothesis is defined as a statistical hypothetical statement which is…

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A: Given data is appropriate for testing of hypothesis to test z-test for single mean because it is a…

Q: The board of examiners that administers the real estate brokerʹsexamination in a certain state found…

A: Here, mean is µ = 487 and the standard deviation is σ = 72.

Q: In a mid-size company, the distribution of the number of phone calls answered each day by each of…

A: Solution: Let X be the number of phone calls answered each day by each of the 12 receptionists is…

Q: A credit bureau analysis of undergraduate students' credit records found that the average number of…

A: State the hypotheses. That is, there is no evidence to conclude that the mean number of credit…

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Q: An auditor, pressed for time and on a low budget, is concerned with account errors on customer…

A: From the given information,Sample size = 25,Sample mean = -$23Sample standard deviation =$16

Q: The College Board National Office recently reported that in 2011-2012, the547,038 high school…

A: The given information is:

Q: A graduate student is performing a study on a new antidepressant. The drug is supposed to reduce…

A: The random variable score follows normal distribution. We have to test whether the average score for…

Q: Assume the annual day care cost per child is normally distributed with a mean of ​$6000 and a…

A: The detailed solution is as follows below:

Q: In a multiple-choice examination in Chemistry, students Mikasa and Jean received scores of 82 and…

A: Given problem Given that   In a multiple-choice examination in Chemistry, students Mikasa and Jean…

Q: For a hypothesis test that compares the standard deviations (SD) of two contexts, how is the test…

A: Hypothesis test is used when determine (with conditions )the population parameter from the given…

Q: A realtor claims that in a certain neighborhood, the average house is worth $200,000. Having been…

A:

Q: If IQ scores are normally distributed with a mean of 100 and a standard deviation of 15, what is…

A: The mean is 100 and the standard deviation is 15.

Q: Suppose that the amount of time that takes place for the Bureau of Internal Revenue to send refunds…

A: Solution: 4. Let X be the amount of time. From the given information, X follows normal distribution…