In a survey, 15 people were asked how much they spent on their child's last birthday gift. The results were roughly bell-shaped with a mean of $42 and standard deviation of $10. Find the margin of error at a 90% confidence level. Give your answer to two decimal places.

Q: In a multiple-choice examination in Chemistry, students Mae and Julie received scores of 82 and 65,…

A: We have given that.   X~N( μ , ?^2 )   μ = , ? =   Z-score =( x - μ )/?

Q: A marketing researcher for a phone company surveys 70 people and finds that the proportion of…

A: Solution: a. From the given information, the proportion of customers who are likely to switch…

Q: Given a sample data set with a Standard Deviation of 1.4, what is the Variance of the data set.?…

A: The given value of sample standard deviation is, s = 1.4 Using the standard deviation, the formula…

Q: given certain level of significance, what is the relationship between the confidence interval and…

A: Margin of error: Margin of error is a range of values that lie above and below the sample statistic…

Q: Find the sample size need to find the Population Mean if the margin of error is $105, the confidence…

A: Solution: From the given information, confidence level is 0.95, σ=315 and E=105.

Q: Find the mean and standard deviation for the numbers of sleepwalkers in groups of five.

A: Given: X P(x) 0 0.175 1 0.357 2 0.318 3 0.118 4 0.028 5 0.004

Q: Given that the mean of a data set is 20, and the standard deviation of this data set is 8, then what…

A: According to the answering guidelines, we can answer only one question at a time and the rest can be…

Q: You are conducting a quantitative research on the study habits and academic performance of the…

A: From the provided information, Standard deviation (σ) = 8 Confidence level = 95% Margin of error (E)…

Q: Among various ethnic groups, the standard deviation of heights is known to be approximately three…

A:

Q: If you have 100 people in your sample, what would be the degrees of freedom you use to calculate the…

A: Given, n=100 Degree of freedom(df)=?

Q: Among various ethnic groups, the standard deviation of heights is known to be approximately three…

A: Using Excel formula “=NORM.S.INV(1-(0.04/2))”, the critical value for 96% confidence level is…

Q: In a study by Sallie Mae and Gallup, 223 of the 934 respondents said that they paid for their…

A: Obtain the 95% confidence interval for the proportion of students who paid for their education by…

Q: If the variance of a particular data set is 7.5820, the standard deviation is

A: We know that variance is the average squared distance from the mean value. And the standard…

Q: In a situation where the sample size was decreased from 39 to 29 in a normally distributed data set,…

A: Confidence interval formula is given by

Q: What is the standard deviation for the following sample of scores? Scores: 3,2,4,6,6,3

A: The standard deviation is a measure of dispersion. It tells how much data are deviates from their…

Q: If the variance of a national accounting examination is 900, how large a sample is needed to…

A:

Q: If you knew that a study reported that 73% of pre-kindergarten children ages 3 to 5 whose mother had…

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Q: The Cpa practice advisor reports that the mean preparation fee for 2017 federal income tax returns…

A: From the provided information, Mean (µ) = $273 Standard deviation (σ) = $100 X~N (273, 100) Here X…

Q: In a study by Sallie Mae and Gallup, 323 of the 1404 respondents said that they paid for their…

A:

Q: A standardized memory test has a mean of μ=100 and a standard deviation of σ = 10. Answer the…

A: (c )   Obtain the scores that separate the middle 28%. The scores that separate the middle 28% is…

Q: 9) In a class of 30 students, how many students failed the test (below 64), if the mean grade on a…

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Q: In a survey of a group of men, the heights in the 20-29 age group were normally distributed, with a…

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Q: In a study of Ridge View's boys' basketball team, the average height is 68 inches and standard…

A: Given, mean =μ=68Standard deviation = 4x = 78

Q: A bank wishes to estimate the mean credit card balance owed by its customers. The population…

A: Determine the number of customers needs to be sampled. The number of customers needs to be sampled…

Q: reported that the 27-year-old mother of three worked, on average, a 75 hour week. Recently, many…

A: As the population standard deviation is not known, we will use a t-test. The null and alternative…

Q: 1. The standard deviation provides an overall measurement of how much participants' scores differ…

A: Given data: The standard deviation provides an overall measurement of how much participants' scores…

Q: The final exam scores in a statistics class were normally distributed with a mean of 63 and a…

A: The final exam scores in a statistics class were normally distributed with a mean of 63 and a…

Q: Consider a sample with a mean of 500 and a standard deviation of 100. What are the z-scores for the…

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Q: An investigative reporter contacts a random sample of hotels, and finds a 95% confidence interval…

A: Given that  The 95% confidence interval for the proportion of hotels in the united states have…

Q: If you knew that I study reported that 67% of pre-kindergarten children ages 3 to 5 whose mother had…

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Q: A travel agency wishes to estimate, at 99% confidence and to within $100, the mean airfare for…

A: According to the given information, we have Standard deviation = $275 Margin of error = $100…

Q: See Table 2 above and answer the following questions:   What can you conclude from the above…

A: “Since you have asked multiple question, we will solve the first question for you. If youwant any…

Q: Grace Floral Shop claims that their average daily earnings is $497. An auditor wants to determine…

A: From the provided information, Sample size (n) = 100 Sample mean (x̅) = 495 Sample standard…

Q: If X̅ = 65, ? = 20 ??? ? = 36, construct a 95% confidence interval estimate for the population mean,…

A:

Q: If a confidence interval for the mean is (41≤μ≤84)(41≤μ≤84), a) What is the point estimate?    b)…

A: a) What is the point estimate?

Q: If the variance of a national accounting examination is 900, how large a sample is needed to…

A: Solution

Q: Allan, a Grade 12 senior high school student, wants to estimate the average number of students who…

A:

Q: The sample standard deviation is a measure of what?

A: The sample standard deviation is a measure of spread of scores within a sample data.

Q: If you have a sample of n=25, what is the standard error if the population standard deviation is σ =…

A: The standard error of the sampling distribution of the sample mean.

Q: If a confidence interval for the mean is (43≤μ≤82)(43≤μ≤82), a) What is the point estimate?    b)…

A: Given the confidence interval for the population mean in tri-linear inequality form: Hence,

Q: Refer to the accompanying​ table, which describes the number of adults in groups of five who…

A: Mean :-  ∈x = ∑  ×. Px                           ∈x =…

Q: A guidance counselor wishes to determine the mean number of changes in academic major by college…

A: Given that, Standard deviation = 0.45 90% confidence level

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Q: Find the median and the standard deviation of the scaled marks of all the students.

A: According to the answering guidelines,  we can answer only one question and the rest can be…

Q: Many families in California are using backyard structures for home offices, art studios, andhobby…

A: Hey there! Thank you for posting the question. Since your question has more than 3 parts, we are…

Q: Given a sample data set with a Variance of 6.25, what is the Standard Deviation of the data set.?

A:

Q: The average speed of 64 random cars traveling on a certain highway was 80 km/h and the sample…

A: We have given that,  Average speed (x̄) = 80 , standard deviation    (s) = 20, Confidence level(C.I)…

Q: In 1955, Life Magazine reported that the 25-year-old mother of three worked, on average, an 80 hour…

A: Claim : the mean work week has increased for women

Q: What is the sample mean? What is the standard deviation?

A: Use EXCEL Procedure for finding the value of sample mean.   Follow the instruction to obtain the…