A professional skier was trying to decide whether to use a new racing wax for cross-country skis. He decided that the wax would be worth the price if he could average less than 55 seconds to ski a course he knew well, so he planned to test the wax by racing on the course 8 times. His sample of race times found a mean of 53.1 seconds, and standard deviation 7.0 seconds. Is this sufficient evidence he should he buy the wax? Test at a .10 significance level.

Q: Suppose that you are interested in determining the average height of a person in a large city. You…

A: Solution: Given information: n= 400 Sample size  x=63 inches Sample mean s= 6 inches Sample standard…

Q: A food critic wishes to estimate the weights of premium steaks at a five star Texas style…

A: From the provided information, Confidence level = 90% Margin of error (E) = 6 ounces Standard…

Q: Use a = 0.10. Construct a 90% confidence interval on the difference in means. O a. Cl on the mean:…

A: It is given that  Sample mean, x̅1 = 18 Sample mean, x̅2 = 24 Population standard deviations, σ1 =…

Q: A particular fruit's weights are normally distributed, with a mean of 639 grams and a standard…

A: The population mean and standard deviation are 639 grams and 36 grams respectively. It is given that…

Q: A particular fruit's weights are normally distributed, with a mean of 526 grams and a standard…

A: Given that, Mean = 526 Standard deviation = 36 Sample size = 7

Q: A market researcher wants to estimate the amount of money that a Christmas shopper will spend on…

A: We have to find sample size for given data..

Q: Loretta, who turns 91 this year, has heard that the mean systolic blood pressure among the elderly…

A: The hypothesis for the claim 'mean systolic blood pressure among elderly adults is greater than 120…

Q: health department nutritionist, wishing to construct a survey among a population of teenage girls,…

A: Formula for the sample size needed to estimate a population mean is

Q: A particular fruit's weights are normally distributed, with a mean of 222 grams and a standard…

A: Solution: Let X be the  fruit's weights are normally distributed with mean 222 grams and standard…

Q: Use the z table to find the value k so that 40% of the scores are greater than k.

A: Normal distribution is widely used in statistics . It is very useful in modern times .

Q: A researcher wishes to see if there is a difference in the manual dexterity of athletes and that of…

A: Sample mean for athletes x¯1=89 Sample mean for band members x¯2=95 Standard deviation σ=7.4 .…

Q: A nurse at a local hospital is interested in estimating the birth weight of infants. How large a…

A: The confidence level is 0.98 The margin of error  ME=2 The population standard deviation σ=8 The…

Q: A parenting magazine reports that the average amount of wireless data used by teenagers each month…

A: State the null and alternative hypotheses for the test. Fill in the blank below. H0: μ=6:…

Q: t random, then 8% of the time, their mean weight will be greater than how many grams? Give your…

A: According to the sum, A particular fruit's weights are normally distributed, with a mean of 596…

Q: A particular fruit's weights are normally distributed, with a mean of 405 grams and a standard…

A: The normal distribution is the most useful theoretical distribution for continuous variable.  For…

Q: A particular fruit's weights are normally distributed, with a mean of 367 grams and a standard…

A:

Q: oretta, who turns  91  this year, has heard that the mean systolic blood pressure among the elderly…

A: Given: Sample size (n)= 19 Sample mean x¯=130 Sample standard deviation (s) = 20 Hypothesized mean…

Q: To determine whether a new drug designed to lower a person’s heart rate is effective or not, Dr.…

A:

Q: An engineer wishes to determine the width of a particular electronic component. If she knows that…

A:

Q: During rush hour, the traffic speed on a busy highway is found to have mean 42 mph and standard…

A:

Q: The president of a university wants to use the mean of a ma to estimate the average amount of time…

A: Given information Standard deviation σ = 1.40 Confidence interval = 0.99 Significance level(α) = 1-…

Q: Dwight wants to estimate the mean calorie content in beets with 90% confidence.  He believes that…

A: The population standard deviation, sigma is 17. The z-critical value for the 90% confidence interval…

Q: Condé Nast Traveler conducts an annual survey in which readers rate their favorite cruise ship. All…

A: given, Group1: The ships carry 500 passengers Sample size n1=37 Sample average rating x¯1=85.39…

Q: A recent study showed that the average number of sticks of gum a person chews in a week is 16. The…

A: From the provided information, Sample size (n) = 31 Sample mean (x̄) = 14 Population standard…

Q: Please answer the problem applying the steps in testing hypothesis

A:

Q: I also need the standard deviation for the above question.

A:

Q: A professor at a local university noted that the exam grades of her students were normally…

A: The mean is 73 and the standard deviation is 11.

Q: A market researcher wants to estimate the amount of money that a Christmass hopper will spend on…

A:

Q: An office manager claims that the mean time required to handle a customer complaint is more than 30…

A: To compare the population mean with the sample mean, either t or z tests would be perform. To use t…

Q: A particular fruit's weights are normally distributed, with a mean of 208 grams and a standard…

A: We have to find mean value for given  data .

Q: Naini, Cobourne, McDonald and Donaldson (2008) reported that a specific ratio of height to face…

A: According to the provided data, it is reported that a specific ratio of height to face length of 1…

Q: In the general population, the mean IQ is 100 with a standard deviation of 15. Dr. Robbins wants to…

A: From the provided information, Population mean (µ) = 100 Population standard deviation (σ) = 15

Q: A 1995 study shows that since records were first kept in a meteorologist's hometown, the average…

A: Solution: Let X be the temperature during the month of May. From the given information, n=25,…

Q: A university dean wishes to estimate the average number of hours that freshmen study each week. The…

A:

Q: A grocer finds that the cantaloupes in his store have weights with mean 0.7 kg and standard…

A: Given, Mean weight of cantaloupes is 700 gm. Standard deviation is 53 gm

Q: A particular fruit's weights are normally distributed, with a mean of 422 grams and a standard…

A: The following information has been given: The population mean is μ=422. The population standard…

Q: An economist would like to estimate the mean amount of money that a family spends to within $30. If…

A:

Q: To compare the dry braking distances from 30 to 0 miles per hour for two makes of automobiles, a…

A: Given,X1=42, σ1=4.7, n1=35X2=45, σ2=4.4 , n2=35and level of significance α=0.10