A maker of electric vehicles wants to estimate the mean distance travelled between charges for all the electric cars made at a new plant. The firm selects a sample of 40 cars for this study, and finds that the cars in the sample averaged about 100 miles between charges. From prior studies, the standard deviation for the distance between charges is known to be about 20 miles. Construct a 90% confidence interval estimate of the average distance travelled between charges for all the cars from the new plant.

Q: Researchers found that in certain counties in the country, females spend an average of 65 days in…

A: standard deviationσ=4n=36x¯=65

Q: The historical reports from two major networks showed that the mean number of commercials aired…

A: There are two independent samples which are first station and second station. We have to test…

Q: The amount of coffee dispensed by a vending machine is assumed to be normally distributed. A vendor…

A: Here's mean is 5.8 and standard deviation is 0.8. Sample number is 36 and population mean is 6. We…

Q: mean lung capacity for nonsmoking males in the population aged 50 is 2.2 liters. an investigator…

A: Given that  The mean lung capacity for nonsmoking males in the population aged 50 is 2.2 liters =…

Q: A random sample of 20 patrons from a Wolfville restaurant were chosen. Their tips measured in…

A: From the provided information,

Q: An endocrinologist is interested in the effects of depression on the thyroid. It is believed that…

A: Given:

Q: A senior high school student is concerned about attending college because she heard that many…

A: The mean difference between the one sample and the population mean is calculated using the t test.…

Q: university in England and each student in a random sample of 38 female students from the same…

A: The following information has been provided: For Males : Sample Mean 1 (Xˉ1)(\bar X_1)= 282282…

Q: A tire company finds the lifespan for one brand of its tires is normally distributed with a mean of…

A: Solution: Let X be the lifespan for one brand of its tires is normally distributed with a mean of…

Q: During the busy season, it is important for the shipping manager at ShipMundo to be able to estimate…

A: Given, Mean, μ=156 Standard deviation,σ=15

Q: If the variance of a national accounting examination is 828, how large a sample is needed to…

A: Given data: Variance  = 828 Margin of error = 4 points Confidence level = 99 % To calculate the…

Q: A marine biologist is interested in whether the chinook salmon a particular species of salmon in the…

A: The value of sample mean is, x¯=36 The value of margin of error is, ME= 9

Q: When Rajani goes bowling, her scores are normally distributed with a mean of 125 and a standard…

A:

Q: The middle 55% of jobs should be within what range of times?

A: here given, mean = 50 minute standard deviation  = 6 minute

Q: Pyramid Lake is on the Paiute Indian Reservation in Nevada. The lake is famous for cutthroat trout.…

A: Determine the level of significance.   Significance level:    In order to decide how small the…

Q: A researcher is conducting a study to determine the mean trough dosage of medication for a…

A: The following information is provided that is required to compute the sample size: Required…

Q: Dr. Moore wanted to estimate the mean cholesterol level for all adult men living in Hartford... He…

A:

Q: random sample of 15 students was selected from a population size of 100 (normal) in a certain…

A:

Q: The drive distance (in yards) for professional golfers is normally distributed with a mean of 308.04…

A: The normal distribution: A continuous random variable X is said to follow normal distribution with…

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

A:

Q: The breaking strengths of cables produced by a certain manufacturer have historically had a mean of…

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

Q: fitness center is interested in finding a 95% CI for the mean number of days per week that Americans…

A: Given: Xˉ=3.2 s=2.6 n=248  Confidence level = 95% As the population standard deviation is not known,…

Q: The age of managers in particular industry is normally distributed with mean μ=35. A group of 30…

A:

Q: (a) State the null hypothesis Ho and the alternative hypothesis ₁. Ho H₁:0 (b) Determine the type of…

A: given data μ > 1825n = 80x¯ = 1830σ = 60α = 0.05

Q: find the 99% confidence interval of the mean number of miles driven per day by all truckers

A: It is given that  Average = 540 Population standard deviation = 40 Sample size = 90

Q: Men hoping to have children are encouraged to avoid hot tubs or saunas because heating the scrotum…

A:

Q: The breaking strengths of cables produced by a certain manufacturer have historically had a mean of…

A: The provided information is x¯=1756σ=50n=90α=0.05The null and alternative hypothesis is…

Q: The breaking strengths of cables produced by a certain manufacturer have historically had a mean of…

A: As per our guidelines we are supposed to answer only 3 sub-parts of any question so I am solving…

Q: The time needed for college students to complete a certain maze follows a normal distribution with a…

A: t-test: If the given sample size is less than or equal to 30 and sample standard deviation is given.…

Q: When 40 people used Weight Watchers for one year, their mean weight loss was 3.0 lbs and their…

A: The test hypotheses are given below: H0:μ=0 lbsHa:μ>0 lbs From the given information, the…

Q: sample of 37 inchworms in Cititon Park was collected and measured. Their lengths had a mean of 2.56…

A: Given:  Sample size n=37  Sample mean(xbar) x¯ =2.56  Standard deviation( ?)=0.09  To find 95%…

Q: The breaking strengths of cables produced by a certain manufacturer have historically had a mean of…

A: We have given that  Sample size n =150 Sample mean =1878 Population standard deviation =50 NOTE:-…

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: formulas.) (a) State the null hypothesis  H0  and the alternative hypothesis  H1 . H0: H1: (b)…

A: Sample size=n=90Sample mean=x̄=1964Population standard deviation=σ=50Note: According to bartelby…

Q: The amount of time it takes students to travel to school can vary greatly depending on how far a…

A:

Q: random sample of 36 people in Edirne city was asked how much their monthly income was. The sample…

A: Given: Sample size (n) = 36 Sample standard deviation (s) = 1200 Sample mean x¯=16000 Confidence…

Q: research firm supplies manufacturers with estimates of the sales of their products from samples of…

A: Given Data : For Sample 1 x̄1 = 41 n1= 50 s1= 11 For Sample 2…