The director of vehicle maintenance for a large mass transportation authority wants to know the average life of bus tires for the fleet of 1,800 busses. A random sample of 100 tires is studied and the mean life is 20,000 miles, with a standard deviation of 1,200 miles. Construct and interpret a 95 percent confidence interval for the true life of tires 2.

Q: a manufacturer claims that the mean lifetime of its fluorescent bulbs is 1050 hours. a homeowner…

A: Given n=40 Standard deviation =80 Xbar=1030 Level of significance=0.05 Mu0=1050

Q: It takes an average of 13.6 minutes for blood to begin clotting after an injury. An EMT wants to see…

A: Given,sample size(n)=43sample mean(x¯)=15.2standard deviation(s)=3.16α=0.01

Q: The scores on a standardized test are normally distributed with a mean of 95 and standard deviation…

A: Given that, The scores on a standardized test are normally distributed with, Mean = 95 Standard…

Q: It takes an average of 8.6 minutes for blood to begin clotting after an injury. An EMT wants to see…

A: From the provided information, Sample size (n) = 65 Sample mean (x̅) = 8.7 Standard deviation (σ) =…

Q: It takes an average of 8 minutes for blood to begin clotting after an injury. An EMT wants to see if…

A: Given The data is as follows: Pop. mean, μ=8Sample size, n=62Sample mean, x¯=7.8Sample sd,…

Q: A sociologist found that in a sample of 50 retired men, the average number of jobs they had during…

A: Given that  Sample size=50 , Mean=6.9 Population Standard deviation=2.3

Q: A set of wrist watch prices are normally distributed with a mean of 76dollars and a standard…

A: From the provided information, Mean (µ) = 76 Standard deviation (σ) = 10 X~N (76, 10) Here X be a…

Q: A study conducted by the Center for Population Economics at the University of Chicago studied the…

A:

Q: A household spends on average of P5,500 for a 2-week period grocery items. The variable is normally…

A: Given,mean(μ)=5500standard deviation(σ)=700

Q: For a random sample of  70  overweight men, the mean of the number of pounds that they were…

A: given data  n = 70 x¯ = 28 poundsσ = 3.8 poundsbest point estimate for population mean  = ?

Q: The mean of a normal set of data is -5.4 and the standard Deviation is 22.5 sketch a normal curve…

A: We have to plot a Normal curve with the given data  , Mean = -5.4 standard deviation = 22.5.

Q: A simple random sample of 64 observations was taken from a large population. The sample mean and the…

A:

Q: The weights of men are normally with a mean of 172 pounds and a standard deviation of 29 pounds.…

A: Let X be the random variable from normal distribution with mean (μ) = 172 and standard deviation (σ)…

Q: The scores on a standardized test are normally distributed with a mean of 85 and standard deviation…

A: Since z-score is a measure of how far the standard deviation is away from the mean (Above/below).…

Q: Assume that adults have IQ scores that are normally distributed with a mean of 95.6 and a standard…

A: Given: x~N(μ,σ)μ=95.6σ=24.3

Q: A bank loan officer rates applicants for credit. The ratings can be described by a normal model with…

A: Given: μ = ​200 σ = 50

Q: The width of an A4 piece of paper is  normally distributed with a mean of 210  mm and a standard…

A: The width of an A4 piece of paper is normally distributed with a mean of 210 mm and a standard…

Q: r blood to begin clotting after an injury. An EMT wants to see if the immediately told the truth…

A: According to guidelines we solve first three subparts when given multiple subparts.

Q: A sample of 77 subjects went on a low-carbohydrate diet for six months. At the end of that time, the…

A: Given that  Sample size n1=77 , n2=79 Sample means x1=4.7 , x2=2.6 s1=7.16 , s2=5.9

Q: Assume that adults have IQ scores that are normally distributed with a mean of 103.8 and a standard…

A:

Q: me that the heights of women are normally distributed with a mean of 62.9 inches and a standard…

A: To calculate the 75th percentile of a normal distribution, we used the formula as: X=μ+Zσ Where 'X'…

Q: Assume that adults have IQ scores that are normally distributed with a mean of 100.7 and a standard…

A: Given Data : Population Mean,μ = 100.7 Population Standard Deviation,σ = 18.9

Q: The daily water usage per person in Davao City is normally distributed with a mean of 20 gallons and…

A: Empirical Rule : The empirical rule, also referred to as the three-sigma rule or 68-95-99.7 rule, is…

Q: An environmental researcher took 30 water samples from different areas of a lake. He measured the pH…

A: The objective of the question is to understand the concept of standard deviation and interpret it in…

Q: If the weight of fertilizer in a 40-pound bag is normally distributed with a standard deviation of…

A: Define  the Random Variable, X : Weight of fertilizer in the bag. X ~ N(40,0.52) Hence , the mean, µ…

Q: The mean for data set is 59, the standard deviation is 4, and the z- score is 0.03, what is the raw…

A: Here given that the mean =59, standard deviation=4, z score=0.04, we need to find the raw score x.

Q: The mean speed of vehicles along a stretch of highway is 75 miles per hour with a standard deviation…

A: Given Information: Mean, μ=75 miles per hour Standard deviation, σ=3.8 miles per hour Current speed,…