1. A recent study of 25 motorists showed that they spent an average of P750 per week. The standard deviation of sample was P90. Find the 99% confidence interval of the true mean.

Q: We notice a mean loss of 7 pounds in a sample of 11 dieters, with a standard deviation of three…

A: We first find the critical value for 95% confidence interval

Q: For a sample of n = 30 scores, a score that is 6 points above the mean has a z-score of z = 1.50.…

A: For a sample of n = 30 scores, a score that is 6 points above the mean has a z-score of z = 1.50.

Q: If you know that you have data that follows a normal distribution with a mean of 75 and standard…

A: Solution: Let X be the random variable. From the given information, X follows normal distribution…

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

A: The mean is 500 and the standard deviation is 100.

Q: Find the 2-score for a raw score of 27 with a mean of 20 and a standard deviation of 5. O-06 O 14 O…

A:

Q: If a set of data has a mean of 12 and a standard deviation of 3, what is the z-score for a value of…

A:

Q: For a population with mean 80 and standard deviation 6, what is the z-score corresponding to X = 68…

A: Given :Population mean u=80Standard deviation σ=6X=68

Q: 3. Suppose the mean blood glucose of a population of adults is 162 with a standard deviation σ=58.…

A: Given that, n=36,μ=162σ=58 The mean and standard deviation of sample mean is,

Q: For a population with a mean of 75 and a standard deviation of 12, what proportion of sample means…

A: Given, Mean μ = 75 Standard deviation σ = 12 sample size n = 16

Q: 1. The scores on a test have a mean of 100 and a standard deviation of 15. If a personnel manager…

A: Formula : Z =(X - μ)/σ

Q: For a population with a standard deviation of σ = 20, how large is a sample  necessary to have a…

A: The standard deviation is 20.

Q: 8, and the sample standard deviation, s, is found to be 4.6. ...

A:

Q: Given that a set of scores have a normal distribution, a mean of 74, and a standard deviation of 5:…

A:

Q: W 4. A cell phone company claims that the average time a person spends on their phone is 12.8 hours…

A: Let μ denote the population mean and x⎯⎯ denotes the sample mean. Then, μ=12.8 and x⎯⎯=12.2 Let n be…

Q: A researcher wishes to estimate within $5 the average repair cost of for a refrigerator. If she…

A: Population standard deviation is 15.50. The z-critical value for 90% confidence interval is 1.645…

Q: 2. Given a standard deviation of 3.7, what is the mean if1 0% of the population has a distribution…

A: We have given that,  Let x be the random variable from normal distribution with standard deviation…

Q: 1. Miss Romero noted that the mean scores of a random sample of 15 Grade 8 students who had taken a…

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

Q: For a population with a standard deviation of 20, what is the zscore corresponding to a score that…

A: The population standard deviation is 20. The z-score corresponding to a score that is 5 points below…

Q: If 10 were added to each of the values in a data set that originally had a standard deviation of 6,…

A:

Q: A score that is 6 points below the mean corresponds to a z-score of z = -2.00. What is the…

A: Given: z-score = -2.00 Formula: Where,

Q: For a random sample of 40 students, the average statistics midterm score is 73 points (out of a…

A: The sample size is 40, average statistics midterm score is 73 points, and standard deviation is 7.3.

Q: If you have a population standard deviation of 10 and a sample size of 4, what is your standard…

A: Given,population standard deviation(σ)=10sample size(n)=4

Q: If the standard error of the mean is σx̅ = 3 and the sample size is n= 64,then the population…

A:

Q: The current government economic survey wishes to know, with 96% confidence, the average household…

A:

Q: For a population with a mean of μ = 24 and a standard deviation of σ = 14, find the z-score…

A: Given,mean(μ)=24standard deviation(σ)=14sample size(n)=4sample mean(M)=26

Q: The population standard deviation for the height of high school basketball players is three inches.…

A: Solution: 6. From the given information, confidence level is 0.95, σ=3 inches and E=1.

Q: with a sample average of 80 and a raw score of 76. Would you prefer a standard deviation of s=2 or…

A: A standard deviation of s=2 is preferred.

Q: Given that the mean score is 83 and the standard deviation is 6. What z-score corresponds to the…

A:

Q: A custodian wishes to compare two competing floor waxes to decide which one is best. He believes…

A:

Q: In order to set rates, an insurance company is trying to estimate the number of sick days that full…

A:

Q: In order to set rates, an insurance company is trying to estimate the number of sick days that full…

A: Given Margin of error=1 Standard deviation=3.6 Significance level=0.05

Q: If the standard error of the mean is σx̅ = 3 and the sample size is n = 64, then the population…

A:

Q: If you draw a sample of 200 from a normal distribution and using the Empirical Rule; how many data…

A: Given dataSample size(n) = 200In normal distribution, as per empirical formulaApplying empirical…

Q: THE SCORES ON THE SAT MATH HAD A MEAN OF 431 AND A STANDARD DEVIATION OF 117. What percent of…

A:

Q: Suppose the standard deviation of the losses had been $3600 instead of $1800. What would the larger…

A:

Q: Miss Romero noted that the mean scores of a random sample of 15 Grade 8 students who had taken a…

A: Given: Sample size, n=15 Let PE denote point estimate Sample mean, x¯=80.5sample standard deviation,…

Q: For a population with mean of 50 and a standard deviation of 8, what is the Z-score that corresponds…

A: Given:  population mean of random variable x is =50 and standard deviations=8  then find z score…

Q: If the mean score on a math quiz is 12.6 and 38.2​% of the students in your class scored between…

A: Mean = 12.6 area between 11.1 and 14.1 is 38.2%

Q: If the average low temperature of a winter month in Rochester, NY is 18∘18∘ and the standard…

A: According to the Chebyshev's theorem, 1-(1/k²) of the observation fall within k standard deviation…

Q: If the mean is two, and the standard deviation is one, would a value of five be considered…

A: Unusual values : Unusual values should be lie outside the 2 standard deviation from the mean.   i.e.…

Q: (O) What is the standard deviation of a distribution that has a mean of 46.2 if a PERFORMANCE value…

A: From the provided information, Mean (µ) = 46.2 Performance value (x) = 28 Z score = -1.24

Q: Suppose that the scores on a statewide standardized test are normally distributed with a mean of 70…

A: Let , X denotes  scores on a statewide standardized test .  Therefore , X - > N (mean = 70 , sd =…

Q: According to Chebyshev's Teorem, at least what percentage of snake lengths are within K= 2.9…

A: The Chebyshev’s rule states that, for any quantitative data set and any real number greater than k,…

Q: The mear was 80 and the Standard deviation was 4, Kawhi scored 5, 8o his z-Score was more than one…

A:

Q: For a sample, a score that is 12 points above the mean has a z-score of z = 1.20. What is the sample…

A: We have to find sample standard deviation

Q: for a population with a standard deviation of 4.2 and mean of 32.5, draw a bell shaped curve,…

A:

Q: Given IQ scores are approximately normally distributed with a mean of 100 and standard deviation of…

A: From the given information,   Mean = 100 Standard deviation = 15   The objective is to find the…

Q: In order to set rates, an insurance company is trying to estimate the number of sick days that full…

A:

Q: A statistics professor announces that 15% of the grades he gives are As.  The results of the final…

A: Solution:From the given information, mean score is 83, standard deviation is 6. The fifteen…