The manufacturer of a certain brand of auto batteries claims that the mean lifè of these batteries is 40 months. A consumer protection agency that wants to check this claim took a random sample of 24 such batteries and found that the mean life for this sample is 42 months. The lives of all such batteries have a population standard deviation of 4.5 months. Perform a hypothesis test at 10% significance level and state your decision using critical value approach.

Q: A researcher wants to test the claim that convicted burglars spend an average of 18.7 months in…

A: Null hypothesis: µ=18.7. Alternative hypothesis: µ≠18.7. This is a two-tailed test. Here, the sample…

Q: A random sample of 21 Camden County College students had a mean age of 24 years, with a standard…

A:

Q: Researchers interested in determining the relative effectiveness of two different drug treatments on…

A:

Q: A laboratory tested 58 chicken eggs and found that the mean amount of cholesterol was 109…

A: Given Information: Sample size (n) = 58 Sample mean (x¯) = 109 milligrams Population standard…

Q: In a random sample of 23 private school teachers in queens county the average teaching experience is…

A:

Q: Researchers were interested in how characteristics of the spleen of residents of Nigeria compared to…

A: Solution: Given information: n1= 91 Sample size of males n2= 109  Sample size of females x1= 11.1 cm…

Q: Your research group has been hired to determine if college men and women drink different amounts of…

A: We have to calculates the z-score.

Q: A college admissions officer for the school’s online undergraduate program wants to estimate the…

A: The objective of this question is to determine whether the true mean age of online undergraduate…

Q: A local grocery store manager was tracking the amount of water customers purchased during the…

A: Consider that μ defines the population mean amount of water purchased by Americans.

Q: Researchers from a certain country were interested in how characteristics of the spleen of residents…

A: Given that n1=93, x¯1=11.1, s1=0.9, n2=107, x¯2=9.9, s2=0.8, α=0.01.

Q: The U.S. Center for Disease Control reports that in year 1900, the mean life expectancy is 48 years…

A: Solution: Given information: n1= 29000  Sample size of white population n2= 96000  Sample size of…

Q: (a). The null and alternative hypotheses are O Ho:ã = 2.3 Ha: + 2.3 Ο H0: μ = 2.8 На: д < 2.8 Ο Ηρ:…

A: Here given  sample statistics  And significance level 0.05

Q: People who diet can expect to lose an average of 3kg in a month. In a book, the authors claim that…

A: given dataclaim: people who follow a new diet will lose an average of less than 3kg in a month.…

Q: You are the manager of a restaurant for a fast-food franchise. Last month, the mean waiting time at…

A:

Q: The mean annual car insurance premium for young drivers in the UK was £1503. A study was conducted…

A: Given information- Sample size, n = 25 Significance level, α = 0.05 Sample mean, x-bar = 1440 Sample…

Q: Researchers from a certain country were interested in how characteristics of the spleen of residents…

A: Males Sample size, n1=93 Sample mean, x¯1=11.2 Sample sd, s1=0.8   Females Sample size, n2=107…

Q: Suppose that a manufacturer of laptop batteries claims that his product last more than 950 hours.…

A: Given data : sample size, n = 45 sample mean, x̄ = 925.0 sample standard…

Q: A hospital administrator noticed a large change in the weight of babies being born at the hospital…

A: Given,sample size(n)=10sample mean(x¯)=7.07population standard…

Q: A study of 43 US presidents was recently performed in order to determine their height. The mean for…

A:

Q: A recent study found that the average exercise time for adults in the United States is 20 minutes…

A:

Q: The president of a university believes the entering class this year has an average ACT score…

A: Hypothesis: The null and alternative hypotheses are below: H0: μ=23H1: μ≠23 The test statistic is…

Q: The mean age when smokers first start is 13 years old with a population standard deviation of 1.8…

A: mu = 13xbar = 12.2s = 1.8n = 32

Q: A New York Times article noted that the mean life span for 6 male symphony conductors was 80.4 years…

A: Given that  Hypothesized Population Mean (\mu)(μ) = 67.167.1 Sample Standard Deviation (s)(s) =…

Q: A local grocery store manager was tracking the amount of water customers purchased during the…

A: Consider that μ defines the population mean amount of water purchased by Americans.

Q: Volunteers who had developed a cold within the previous 24 hours were randomized to take either zinc…

A: " Since you have posted a question with multiple sub-parts, we will solve the first three subparts…

Q: In 2010, the mean years of experience among a nursing staff was 14.3 years. A nurse manager took a…

A: Answer  Population mean μ =14.3 Sample mean = x = 18.37 Sample size = [n] =35 Standard deviation =…

Q: The class that graduated from a college four years ago took an average of 2.3 science courses. Since…

A: Solution

Q: A survey was conducted to determine the average number of hours that people spend on the internet…

A: GivenMean(x)=3standard deviation(s)=1sample size(n)=100significance level(α)=0.05

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

A:

Q: A random sample of 17 snowmobiles was selected, and the lifetime of the battery was measured. The…

A:

Q: n a scientific study conducted by the Dax Science Lab on Deep Space Nine, 41 male rats were sent to…

A:

Q: You are interested in comparing Ezekiel Elliott’s performance last season to this season. In…

A: 1)  Determine at the 5% significance level if his performance this year when it comes to the average…

Q: A major car manufacturer wants to test a new engine to determine whether it meets air pollution…

A: Given that  Sample size n =10 Sample mean =61.1 Standard deviation =3.0

Q: The sample mean weight of 200 adult vulturine parrots was measured to be 734.2 grams, with a…

A: Given  x bar = 734.2s = 15.7n = 20 The 90% CI is given by

Q: The manufacturer of a particular brand of tires claims they average at least 50,000 miles before…

A: Given information Population mean µ = 50000 Sample size n = 21 Sample mean x̅ = 46500 Standard…

Q: The mean number of English courses taken in a two-year time period by male and female college…

A:

Q: A nurse in the immunization clinic claims that the mean age at which children start walking is 12.5…

A: The null and alternative hypothesis is obtained below:                        The claim of test is…

Q: Researchers from a certain country were interested in how characteristics of the spleen of residents…

A: That is, there is no evidence to conclude that there is a difference exists in the mean spleen…

Q: A number of 28 university students who smokes completed a questionnaire inquiring their smoking…

A: Test Statistic for Difference of two means is given by,   Hypothesis, Ho:the smoking initiation age…

Q: Explain what would happen to the length of the interval if the confidence level were decreased to…

A: Here Given  Sample size=n=60 Sample mean=x¯=12.88 And From Normal table Critical values for  95 C.I…