A scrap metal dealer claims that the mean of his sales is “no more than $80,” but an Internal Revenue Service agent believes the dealer is untruthful. Observing a sample of 20 cash customers, the agent finds the mean purchase to be $91, with a standard deviation of $21. Assuming the population is approximately normally distributed and using the 0.05 level of significance, is the agent’s suspicion confirmed?

Q: In a recent year, the scores for the reading portion of a test were normally distributed, with a…

A: Mean is 20.4 and the standard deviation is 6.5.

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: Recent Environmental Protection Agency (EPA) fuel economy estimates for automobile models tested…

A: Given that Mean(µ) = 24.8 Standard deviations (σ) = 6.2

Q: On a scale designed to measure attitudes toward immigration, two college classes scored as follows.…

A: Question 8: Class A: The value of mean for class A is, Mean=∑ixiN=4+6+2+1+1+16=156=2.5 Thus, the…

Q: Given the previous problem where Rashid is 84 inches tall and that the height of male in the United…

A: We will consider one of the most remarkable results in probability namely the central limit theorem.…

Q: The Department of Transportation of the State of New York claimed that it takes an average of 200…

A:

Q: 3. The average age of the marketing executives in an ad agency is 26, with a standard deviation of…

A: Note : Since you have asked multiple questions, we will solve the first question for you. If you…

Q: Suppose, at a local movie theater, the amount of money that a man spends at the concession has an…

A:

Q: A trucking company determined that the distance traveled per truck per year is normally distributed,…

A: Here, mean is 60 thousand and standard deviation is 10 thousand. a. The proportion of trucks can be…

Q: The heights of a pediatricians three-year-old females are approximately normally distributed, with…

A:

Q: When Boubacar commutes to work, the amount of time it takes him to arrive is normally distributed…

A: we have to find out given probability ...

Q: An employer claims that full time employees have a mean income of $35,000. A sample of 200 employees…

A: From the provided information, The hypotheses can be constructed as: Null hypothesis: H0: µ =…

Q: A trucking company determined that the distance traveled per truck per year is normally distributed,…

A: Given Information: Mean (u) = 30 thousand miles  Standard deviation (s) = 12

Q: c. Find P(X>40).

A: Let X denote the automobile mileage ratings. Given that X follows N(mean = 37, SD = 1.4), then Z =…

Q: "According to Dietary Goals for the US (1977), high sodium intake may be related to ulcers, stomach…

A: Claim : the average sodium content for a single servings of noodles is less than 220 milligrams.

Q: If the standard deviation of sample A  is 5 and the standard deviation of sample B  is 12, what is…

A:

Q: Compute for the median, and standard deviation of the given data

A:

Q: In a certain supermarket, a sample of 60 customers who used a self-service checkout lane averaged…

A: Introduction: Assume that the checkout times of the customers are independent of each other, between…

Q: The mean annual tuition and fees for a sample of 15 private colleges was $41,200 with a standard…

A: Given: n=15x¯=41200s=5300μ=38000α=0.05 The test hypothesis are, H0: μ=38000H1: μ≠38000. This is a…

Q: Given a mean price of a residential real estate sales of KD 527,000 and a standard deviation of KD…

A: To find the probability of: a) having a sale above KD 550,000 b) having a sale below KD 527,500

Q: With a sample of 62, a population mean of 29, and a standard deviation of 9, what is the standard…

A: Givensample size(n)=62population mean(μ)=29standard deviation(σ)=9

Q: Given a sample data set with a Standard Deviation of 1.34, what is the Variance of the data set.?…

A: We have to find variance.

Q: The quality-control manager at a light bulb factory needs to determine whether the mean life of a…

A:

Q: Find the standard deviation for the grouped data.

A: Solution; Interval Frequency (f) midpoint(x) fx (x-x)2 f*(x-x)2 50-59 7 54.5 381.5 351.5625…

Q: A community health plan wishes to estimate the mean number of visits per plan participant in a year.…

A: Given that Margin of Error, E = 2 Population SD = 6.3 Level of confidence = 0.95 The critical value…

Q: years. A survey of companies reported in The Wall Street Journal found a sample mean tenure of x =…

A: (a)   The following null and alternative hypotheses need to be tested: Ho: \muμ ≥ 99 Ha: \muμ <…

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: Is the standard deviation of the sample a good estimate of the variation of salaries of TV…

A: Sample standard deviation is always an unbiased estimate of population sd.

Q: that empty homes are not as appealing to buyers as staged homes and, therefore, sell for lower…

A: The following information has been provided: Sample Mean 1 (\bar X_1)(Xˉ1​) = 150000150000…

Q: A trucking company determined that the distance traveled per truck per year is normally distributed,…

A: A normal distribution is a continuous type probability distribution.It is also known as a…

Q: Antelope Coffee, Inc., is considering the possibility of opening a gourmet coffee shop in Big Rock,…

A: mean = μ = 70000 standard deviation = σ = 5000

Q: For a population with a mean of μ = 45 and a standard deviation of σ = 10, what is the standard…

A: Obtain the standard error of the distribution of sample means for sample size n=4 scores. The…

Q: claims that Chip Ahoy Cookies have an x ̅=28.67 per cookie with a SD=2.67. Assuming this information…

A: Given data,Mean x=28.67sd    =2.67  what is the population parameter for the standard deviation?

Q: In determining automatic mileage ratings, it was found that the mog in the city for a certain model…

A:

Q: An employer claims that full time employees have a mean income of $35,000. A sample of 200 employees…

A:

Q: examination. Scores on the GMAT are roughly normally distributed with a mean of 527 and a standard…

A: Given data,μ=527σ=112P(X>437)=?

Q: A college professor noted that the grades of his students in an introductory statistics class were…

A: Given that, Mean = 52.50 Standard deviation = 9

Q: The inspection division of the Lee County Weights and Measures Department is interested in…

A:

Q: A firm’s marketing manager believes that total sales for next year will follow the normal…

A: Given information- Population mean, µ = $3200,000 Population standard deviation, σ = $250,000 We…

Q: The hotel industry has been greatly impacted by the COVID-19 pandemic. Suppose that traditionally…

A:

Q: For a population with a mean of μ = 55 and a standard deviation of σ = 17, what is the standard…

A: We have to find correct answer..

Q: Assuming that the heights of college women are normally distributed with mean 68 inches and standard…

A: Given Mean=68 Standard deviation=3

Q: if you have a population standard deviation of 19 and a sample size of 4, what is your standard…

A: Given,standard deviation (σ)=19sample size(n)=4

Q: The amount paid for a particular model car is normally distributed with a mean of $15,300 and a…

A:

Q: The Downtown Parking Authority of Tampa, Florida, reported the following information for a sample of…

A: We are given a table.

Q: sample of 25 cappuccinos shows a mean of 42.1 oz of espresso and a standard deviation of 0.38 oz. A…

A: Given: Sample size, n = 25 Sample mean,  = 42.1 Standard deviation, s = 0.38

Q: Rosencrantz and Guildenstern are on a weight-reducing diet. Rosencrantz, who weighs 178 lbs.,…

A: Given data,For RosencrantzMean =145sd=15Weight is x=178For GuildensternMean =165sd=20Weight is x=204

Q: Assuming the sample mean and standard deviation are indicative of the class as a whole, in what…

A:

Confidence Intervals

When we calculate intervals in probability and statistics, it can be simply termed as finding out a confidence interval. The confidence interval is usually calculated from the data set which is observed. The value of the parameter that needs to be calculated is present here only.