According to a sports report, the time of finishers covering a certain distance is normally distributed with a standard deviation of 9 minutes. Find the percentage of samples of 4 finishers that have finishing time less than 5 minutes of the population mean finishing time.

Q: The average American family of four spends $5,000 per year on food prepared at home. Assuming a…

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Q: If a population has a mean of 228.8 and a standard deviation of 35.5 then a sampling distribution…

A: Given that, mean is 228.8 and standard deviation is 35.5. We will use z-standard normal…

Q: Last year, the numbers of skateboards produced per day at a certain factory were normally…

A: Here we use the formula ; z=(x-mean)/standard deviation

Q: According to a recent survey, the salaries of assistant professors have a mean of $40,756 and a…

A: Determine the Z score for the random variable X equals 45,000. The Z score for the random variable…

Q: The speeds of all cars on the tollway was found to be normally distributed with a mean of 63 miles…

A: It is given that that µ=63 mile per hour. Obtain the standard deviation of the speeds of all cars:

Q: According to one pollster, 56% of children are afraid of the dark. Suppose that a sample of size 28…

A: The standard deviation id the sampling distribution of the sample proportion is represented as and…

Q: An advertising agency has stated that 20% of all television viewers watch a particular program. How…

A: From the provided information, An advertising agency has stated that 20% of all television viewers…

Q: The admission committee of AUCA passes 61% of those who took the exam. If the scores follow a normal…

A: We have given that.   X~N( μ , ?^2 )   μ =350 , ? =25   Z-score =( x - μ )/?

Q: The lengths of human pregnancies are normally distributed with a mean of 268 days, and a standard…

A: Given that, X~N(268,152) n=10

Q: The mean annual income for people in a certain city (in thousands of dollars) is 43, with a standard…

A: Given,sample size(n)=91mean(μ)=43standard deviation(σ)=23

Q: The length of adult parakeets is normally distributed. If the mean length is 8 inches with a…

A: Normal distribution is a continuous probability distribution and it has so many real world…

Q: As the size of a sample increases, the standard deviation of the distribution of sample means…

A: Here  Standard deviation of sample mean = σn

Q: The time that a customer takes to complete a transaction in a business line at the bank follows a…

A: Given data,Mean μ=5.4sd    σ=1.7How many minutes will 20% of the customers spend completing a…

Q: . In order for an engineering graduate to enroll in a master’s program, the graduate studies…

A: GivenMean(μ)=420standard deviation(σ)=100

Q: The life span of a car​ tire, calculated in​ miles, is normally​ distributed, with a mean of 70,000…

A: Solution: Let X be the  life span of a car​ tire, calculated in​ miles, is normally​ distributed,…

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

A: Given information- Mean weight of the bears, µ = 80 thousand miles Population standard deviation, σ…

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: Nationally, the per capita monthly fuel oil bill is $110. A random sample of 36 cities in the…

A: Let μ denotes the population mean per capita monthly fuel oil bill. The national per capita monthly…

Q: The total cholesterol levels of a sample of men aged 3544 are normally distributed with a mean of…

A: (a) The random variable X is defined as the total cholesterol levels of a sample of men aged 35-44…

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

A: Solution-: Let, X= The distance traveled per truck per year Given: We find, P[ either less than…

Q: The average number of moves a person make in his/her lifetime is 12 and the standard deviation is…

A: Given,sample size(n)=25mean(μ)=12standard deviation(σ)=3.5

Q: What is the standard deviation of a ribution that has a mean of 46.2 if a FORMANCE value of 28 is…

A: Given information: The mean of the distribution is µ = 46.2 The performance value is x = 28. The…

Q: Find the standard deviation using 2 methods. And identify it is a grouped data or ungrouped data

A: Solution To calculate the standard deviation firstly we will use mid point.

Q: A highway study of 8000 vehicles that passed by a checkpoint found that their speeds were normally…

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Q: A maths class has 100 members. If there is a 15% absentee rate per class meeting , find the standard…

A:

Q: In a standardized exam the mean score is 400 with a standard deviation of 50. If a random sample of…

A: Given that  μ= 400 , σ= 50 , n = 25

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: According to a recent survey, the salaries of assistant professors have a mean of $41,750 and a…

A:

Q: According to a recent survey, the salaries of assistant professors have a mean of $41,750 and a…

A: Solution: Let X be the salaries of assistant professors. From the given information, X follows…

Q: If the average person adds 27 pounds of glass to recycle per year, with a standard deviation of 3,…

A: Mean (µ) = 27 Standard Deviation (σ) = 3 Sample size (n) = 20 Probability that the sample mean…

Q: For women aged 18-24, systolic blood pressures are normally distributed with a mean of 114.8 mm Hg…

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

Q: According to a recent survey, the salaries of assistant professors have a mean of $41,750 and a…

A: Given information: Mean salary of assistant professors μ=$41,750 Standard deviation of salary of…

Q: A history class has 75 members.  If there is a 12% absentee rate per class meeting , find the…

A: Given data  P(absent) = p = 0.12  So q= 1-p = 0.88 Sample size (n)= 75 X = no.  of student absent We…

Q: a small company is looking to see if they have reached their goal of $30.20, in saving per family.…

A:

Q: The standard deviation of the distribution of sample means would be equal to:

A: The standard deviation of the distribution of sample means would be equal to ?

Q: The weight of male contestants is normally distributed with a mean of 96 kg pounds and a standard…

A:

Q: The average number of pages in a novel is 326 with a standard deviation of 24 pages. If a sample of…

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Q: One researcher collected a sample of expenses for advertisement from 5 companies as follows: 50, 60,…

A:

Q: What is the standard deviation of the commuting time?

A: The standard deviation formula for uniform distribution is, σ=b-a12 The commuting time on a…

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

A: Given  mu=209 , sigma=37.8 , n=247 X~Normal(mu=209,sigma^2=37.8^2)

Q: Based from the record, the mean weight of the newborn babies is 4.8 lbs with a standard deviation of…

A: Given that  Population Mean=4.8  Standard deviation=0.75 Sample size=60

Q: An air condition company will spend an average of 64 minutes with a standard deviation of 19 minutes…

A:

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: The average length of a phone call for cell phone users in the United States is 8.4 minutes, with…

A:

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

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

Q: The test scores of 600 students are normally distributed with a mean of 76 and a standard deviation…

A:

Q: According to an article in Good Housekeeping, a 128-lb woman who walks for 30 minutes four times a…

A: Given, Sample size = 35 Sample mean = 9.1 Sample standard deviation = 5   Set up the null and the…

Q: The height of women in the United States is normally distributed with a mean of 165 cm and standard…

A: The normal distribution has curve with bell shape and it is symmetric about the mean. The normal…

Q: According to a recent survey, the salaries of assistant professors have a mean of $41,700 and a…

A:

Q: The weight of trucks traveling on a particular section of Highway 2H has a population mean of 15.8…

A: