Suppose that the amount of sleep college students get per night has a symmetric, bell shaped distribution with mean 6.9 hours and standard deviation of 1.7 hours. (a) Between what two amounts of sleep do the middle 68% of students get? (b) What value is the 97.5th percentile? (c) What percent of values fall between 6.9 hours and 10.3 hours? (d) Would three hours of sleep be an unusual amount? Explain.

Q: An economist wants to find out if there is difference in the monthly expenses of families from…

A: Using t distribution

Q: Suppose that shoe sizes of American women have a bell-shaped distribution with a mean of 8.47 and a…

A: Empirical rule: The probability that the observation under the normal curve lies within 1 standard…

Q: An economist wants to find out if there is difference in the monthly expenses of families from…

A:

Q: An automobile insurance company claims that its rates for teenage drivers average $470 less per year…

A: Given: population mean = 470sample size=30sample mean = 435std deviation =65

Q: The total cholesterol levels of a sample of men aged 35-44 are normally distributed with a mean of…

A: Given:μ=219 and σ=36.6Sample size = n = 247We have to find how many would you expect to have a total…

Q: According to a recent survey, the population distribution of number of years of  education for…

A: What is the standard error of mean?

Q: if an approxemitly  bell shaped distribution has a mean of 30 and standard deviation of 5, what…

A: Given that  X~N( μ = 30 , ? = 5 ) μ = 30 , ? = 5 Formula for Z-score Z-score =( x - μ )/?

Q: What is the degree of freedom between groups? What is the degree of freedom within groups? What is…

A: The provided information is There are 10 families in Makati and 12 families in Quezon. a=10, s=12…

Q: illustrates the effect of the standard deviation & the type of test (one-tailed or two) on the…

A: Given that, Power of a hypothesis test: The probability of not committing a Type II error is called…

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

A:

Q: The combined math and verbal scores for students taking a national standardized examination for…

A: Given  mean of 670 and a standard deviation of 220.

Q: What value lies under a standard score of 1.5 in a distribution having a mean of 55 and standard…

A:

Q: A sample of assistant professors on the business faculty at state-supported institutions in Ohio…

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

Q: A quality control company was hired to study the length of meter sticks produced by a certain…

A: The mean length would be at the 92nd percentile is obtained below: here, P (Z < z) = 92% P (Z…

Q: The amount of money raised by Clayton State teams for the Statistics Games is normally distributed,…

A: As per our guidelines we are suppose to answer only one question. Given,mean(μ)=$360standard…

Q: An economist wants to find out if there is difference in the monthly expenses of families from…

A: Given that

Q: A study of the Physics and Astronomy department has found that 95% of the graduate students drink…

A: Explanation:Here given the two means and find out the standard deviation of the sample follows the…

Q: Suppose the scores of students on an exam are normally distributed with a mean of 454 and a standard…

A:

Q: An economist wants to find out if there is difference in the monthly expenses of families from…

A:

Q: The credit card balances on 1,000 accounts at the Jefferson Valley Bank have a mean of $760 and a…

A: mean = 760 s = 120 n = 1000

Q: If there is no association between color and clarity, what is the standard deviation of resulting…

A: Number of clarity levels a = 5 Number of colors b = 4

Q: In Melanie's Styling Salon, the time to complete a simple haircut is normally distributed with a…

A: Given, Mean = μ =25SD = σ =4

Q: Suppose that IQ scores have a bell-shaped distribution with a mean of 104 and a standard deviation…

A: Given, Mean, mu= 104 Standard deviation, sigma= 17 We know that,  Z score= (X-mu)/sigma

Q: In order to increase customer service, a muffler repair shop claims its mechanics can replace a…

A: Given: x¯=11.6s=2.1n=6 Hypothesis: Null hypothesis: H0: μ=12Alternate hypothesis: H1: μ<12 The…

Q: Why is pooled standard deviation a better estimate of σ than the standard deviation from any other…

A:

Q: In an article in the Journal of Management, Joseph Martocchio studied and estimated the costs of…

A: If the sample size (n) is large (greater than or equal to 30), then the sample mean follows normal…

Q: A company claims that the time their customers spend waiting in line for service is normally…

A: Given that  The company claims that the time their customers spend waiting in line for service…

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: Suppose the durations of human pregnancies follow a mound-shaped distribution with a mean of 266…

A:

Q: Suppose that that the average BMI of the patients at Beth Israel Deaconness Medical Center is 30…

A:

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

A:

Q: Suppose that employees at a large company have salaries that are normally distributed, with a mean…

A: We have given that, Let X be a random variable i.e. salaries of employees are normally distributed…

Q: The students of a large university in Luzon were studied regarding their hours of sleep at night.…

A: As the distribution of the hours of sleep can be modeled as normal distribution with mean μ of 6.9…

Q: An economist wants to find out if there is difference in the monthly expenses of families from…

A:

Q: When a distribution is bell-shaped, approximately what percentage of data values fall within 1…

A: We know that, the empirical rule which is also known as 68-95-99.7 rule.  The Empirical Rule finds…

Q: At Pacific Freight Lines, bonuses are given to billing clerks when they complete 300 or more freight…

A: Given information Mean µ = 270 Standard deviation σ = 16 proportion of the time should a randomly…

Q: Suppose that the heights of 4-year old boys are normally distributed with a mean of 103cm and a…

A: Let X be the random variable from normal distribution with mean (μ) = 103 cm and standard deviation…

Q: The distribution of the number of hours people spend at work per day is unimodal and symmetric with…

A: Solution-: Given: μ=8hours,σ=0.7hours We find, (a) If Saba’s z-score for his work hours was −1.3 ,…

Q: Suppose that IQ scores have a bell shape distribution with a mean of 105 and a standard deviation at…

A: Solution: Let X represent the IQ scores of students.  The distribution of X is bell shape…

Q: A small centre has found that the number of jobs submitted per day to its computers has a…

A: The empirical rule for variables is as follows: 68% of all possible observations lie within one…

Q: Suppose the scores of students on an exam are normally distributed with a mean of 253 and a standard…

A: From the provided information, Mean (µ) = 253 Standard deviation (σ) = 80

Q: The waiting time for patients at a local walk-in health clinic follows a normal distribution with a…

A: We have to find hypothesis..

Q: Suppose that IQ scores have a bell-shaped distribution with a mean of 103 and a standard deviation…

A:

Q: Suppose the average height of a two year old male is normally distributed with a mean of 34.2 inches…

A: Given, Mean = μ = 34.2standard deviation = σ = 2.9

Q: Suppose that the distance of fly balls hit to the outfield (in baseball) is normally distributed…

A: let X be the distance of fly balls hit to the outfield X~N(mu=260,sigma^2=50^2) n=49 we want to find…

Q: The hotel room rate in Miami, Florida is normally distributed with a mean of $286 per night. Assume…

A:

Q: Suppose that IQ scores have a bell-shaped distribution with a mean of 96 and a standard deviation of…

A: 17. Empirical rule (68 – 95 – 99.7 rule): For a bell shaped distribution (normal) the empirical rule…

Q: Suppose the mean net worth of the resi- dents of Sun City, a retirement community, is $611,000…

A:

Q: An economist wants to find out if there is difference in the monthly expenses of families from…

A: There are two independent samples which are Makati and Quezon City. We have to find the computed…