A SAMPLE SIZE OF 36 WAS DRAWN AND ITS MEAN WAS FOUND TO BE 80. TEST WHETHER THIS SAMPLE COULD HAVE COME FROM A NORMAL POPULATION WITH MEAN 90 AND VARIANCE 225?
Q: A company conducted a study of the listening habits of men and women. One facet of the study…
A: Solution: State the hypotheses. Null hypothesis: That is, there is no difference in the variation…
Q: It currently takes users a mean of 44 minutes to install the most popular computer program made by…
A: Hypothesized mean µ = 44 minutes Sample size (n) = 51 Mean x̅ = 47.8 minutes Standard deviation (s)…
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: It currently takes users a mean of 13 minutes to install the most popular computer program made by…
A: Population mean = ? = 13 Sample S.D = s =2.7 Sample size = n =37 Sample mean = x̅ = 12
Q: An office manager claims that the mean time required to handle a customer complaint is less than 30…
A: Statistical hypothesis testing is an important method in inferential statistics. It is used to test…
Q: currently takes users a mean of 26 minutes to install the most popular computer program made by…
A: Given that Sample size n =51 Sample mean =24.9 Standard deviation =2.7
Q: The average income among a sample of 75 students studying at University of Chichester is found to be…
A: sample size(n)=75Mean()=50standard deviation(s)=13confidence interval=95%
Q: The type of alloy used in manufacturing electric wire is important in reducing resistance. It has…
A:
Q: Dr. Samwell Tarly wants to estimate the number of books checked out of the library in the past year.…
A: It is given that the mean is 10,000 and the standard deviation is 10.
Q: Walleyes found in lake Windermere have a mean length of 18.4 inches with a standard deviation of 4.2…
A:
Q: Ten years ago, the mean age of death row inmates was 44.9 according to the US Dept.of Justice. A…
A: The provided data is,
Q: The time married men with children spend on child care averages 6.1 hours per week (Time, March 12,…
A: The hypotheses can be constructed as: H0: µ = 6.1 H1: µ ≠ 6.1 Sample size (n) = 40 Assume level of…
Q: (a) What is the level of significance? State the null and alternate hypotheses. H0: ?2 = 0.18; H1:…
A: According to the answering guidelines, we can answer only 3 subparts of a question and the rest can…
Q: The fan blades on commercial jet engines must be replaced when wear on these parts indicates too…
A: Given that Sample size (n)=61 Sample variance (s2)=0.29 Level of significance =0.01 Population…
Q: It currently takes users a mean of 37 minutes to install the most popular computer program made by…
A: The objective of this question is to determine if the mean installation time for a computer program…
Q: A researcher wants to predict the effect of a drug on psychomotor coordination scores for a task.…
A: From the provided information,
Q: ates, two color variants of the Eastern Gray Squirrel-gray and black-are found in the rrels in a…
A:
Q: A study of snow in Wyoming has a mean thickness of 68cm. A random sample of 12 snow piles in…
A: From the given information, the claim of the problem is the mean thickness of snow in Washington is…
Q: The fan blades on commercial jet engines must be replaced when wear on these parts indicates too…
A:
Q: A population of Senior High School consits of number 1,2,3,4 and 5 .Compute the mean ,variance and…
A:
Q: A petroleum engineer estimated the chances of drilling a dry well to be around 50% , and chances of…
A: The probability distribution of the amount of oil and the associated probability of drilling is as…
Q: Suppose the average golfer drives the ball around 225.55 yards with a standard deviation of 8.82.…
A: Assume that the random variable x denotes the distance of balls drove by the golfer.
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 researcher at a college hears students complain that they don’t have enough time to in their week…
A: Given that, He knows that three years ago, the mean number of hours per week students spent of…
Q: It currently takes users a mean of 44 minutes to insta made to the program, the company executives…
A: Sample size=51 Sample mean=47.8 Population mean=44 Standard deviation =10.2 Level of…
Q: A psychologist reports that the average length of R.E.M. sleep in his test subjects was 10 minutes.…
A: Hypothesis Testing: Hypothesis is a procedure by which we can tests an assumption regarding a…
Q: If the standard deviation of sample A is 5 and the standard deviation of sample B is 12, what is…
A:
Q: archer wanted to examine the effect of a new math study skills program on se y-five students took…
A: Given that Sample size n =25 Sample mean=85 Sample variance s2 =100 Sample standard deviation s=10…
Q: The population average score on a personality measure is ? = 300 and the population standard…
A: The population average score on a personality measure is 300 and the population standard deviation…
Q: The fan blades on commercial jet engines must be replaced when wear on these parts indicates too…
A: a) The level of significance, α=0.01. As the null hypothesis, assume that the variance of…
Q: It currently takes users a mean of 37 minutes to install the most popular computer program made by…
A: The objective of this question is to perform a hypothesis test to determine if the mean installation…
Q: It currently takes users a mean of 16 minutes to install the most popular computer program made by…
A:
Q: It currently takes users a mean of 26 minutes to install the most popular computer program made by…
A:
Q: Fran is training for her first marathon, and she wants to know if there is a significant difference…
A: Given data,n1=40x1=46.6σ1=4.6n2=45x2=48.8σ2=2.4Compute value of test statistic?
Q: The quality-control manager at a light bulb factory needs to determine whether the mean life of a…
A:
Q: It currently takes users a mean of 37 minutes to install the most popular computer program made by…
A: The hypothesized average time (in minutes) to install the program, μ0=37.The sampled number of…
Q: The fan blades on commercial jet engines must be replaced when wear on these parts indicates too…
A: The null and alternative hypotheses are: H0:σ2≤0.18 mm2 H1:σ2>0.18 mm2
Q: Suppose you are conducting a hypothesis test to determine whether the mean of a normal population is…
A: Given The data is as follows: Sample size, n=100 Sample mean, x¯=29 Sample standard deviation, s=5…
Q: A production engineer wants to determine if two assembly lines are producing the same mean number of…
A: Given: x¯1=110n1=10s12=200x¯2=100n2=15s22=150 Hypothesis: The null and alternative hypotheses are…
Q: A production engineer wants to determine if two assembly lines are producing the same mean number of…
A:
Q: A manufacturer of chocolate chips would like to know whether its bag filling machine works correctly…
A:
Q: A researcher at a college hears students complain that they don’t have enough time to in their week…
A: Introduction: The effect size, as the proportion of sample variance, r2, for a one-sample t-test is…
Q: An employer measured the number of units sold by his 400 sales employees. He noted that 40 woman…
A: Given data n1=40, sample mean x̄1=122, s21=60 n2=35, sample mean x̄2=126, s22=74, level of…
Q: It currently takes users a mean of 26 minutes to install the most popular computer program made by…
A: In hypothesis testing, we start by stating the null hypothesis (H0) and the alternative hypothesis…
A
Trending now
This is a popular solution!
Step by step
Solved in 2 steps with 2 images
- A sample of seven laptop computers had a variance of 25.88 years when the lifespan of the computer was studied. Find the 90% confidence interval for the true variance of the lifespan of laptop computers. Show all work leading up to your answer belowA number of 28 university students who smokes completed a questionnaire inquiring their smoking history and behavior. The result shows that the average smoking initiation age of this group is 21.6 years with a variance of 18.49. Based on past record, the smoking initiation age of university student has a mean of 20.74 years with a standard deviation of 5.1 years. Conduct a necessary analysis to determine if the smoking initiation age remain the same as the previous record. Use 4% level of significance.It currently takes users a mean of 26 minutes to install the most popular computer program made by RodeTech, a software design company. After changes have been made to the program, the company executives want to know if the new mean is now different from 26 minutes so that they can change their advertising accordingly. A simple random sample of 51 new customers are asked to time how long it takes for them to install the software. The sample mean is 24.9 minutes with a standard deviation of 2.7 minutes. Perform a hypothesis test at the 0.025 level of significance to see if the mean installation time has changed. Step 3 of 3 : Draw a conclusion and interpret the decision.
- What is the standard deviation of a sample of 120 observations, if the variance of the sample 2.56?A new drug is being tested to see if it reduces the frequency of migraines. Study participants were divided into two groups. 49 participants in group 1 received the medication; 42 participants in group 2 received a placebo. After a period of six months, group 1 had a mean of 4 migraines. It is known that the population standard deviation for this group is 1.3 migraines. Group 2 had a mean of 5.4 migraines. The population standard deviation for this group is 1.7 migraines. Can we conclude that the medication reduces the population mean number of migraines? Use αα =0.01. Note: If t-test, then unequal variances are assumed. Question a)Let: μ1μ1 = the population mean number of migraines with the medication μ2μ2 = the population mean number of migraines with the placebo (Step 1) State the null and alternative hypotheses by selecting the appropriate symbol, and identify which tailed test: H0:H0: μ1μ1 μ2μ2 H1:H1: μ1μ1 μ2μ2 Which tailed test…Fran is training for her first marathon, and she wants to know if there is a significant difference between the mean number of miles run each week by group runners and individual runners who are training for marathons. She interviews 42 randomly selected people who train in groups and finds that they run a mean of 47.1 miles per week. Assume that the population standard deviation for group runners is known to be 4.4 miles per week. She also interviews a random sample of 47 people who train on their own and finds that they run a mean of 48.5 miles per week. Assume that the population standard deviation for people who run by themselves is 1.8 miles per week. Test the claim at the 0.01 level of significance. Let group runners training for marathons be Population 1 and let individual runners training for marathons be Population 2. Step 2 of 3 : Compute the value of the test statistic. Round your answer to two decimal places.
- Why would the null hypothesis not be the mean lifespan of sexually inactive males (62.5)?The fan blades on commercial jet engines must be replaced when wear on these parts indicates too much variability to pass inspection. If a single fan blade broke during operation, it could severely endanger a flight. A large engine contains thousands of fan blades, and safety regulations require that variability measurements on the population of all blades not exceed ?2 = 0.18 mm2. An engine inspector took a random sample of 81 fan blades from an engine. She measured each blade and found a sample variance of 0.28 mm2. Using a 0.01 level of significance, is the inspector justified in claiming that all the engine fan blades must be replaced? (b) Find the value of the chi-square statistic for the sample. (Round your answer to two decimal places.) Find or estimate the P-value of the sample test statistic. P-value > 0.1000.050 < P-value < 0.100 0.025 < P-value < 0.0500.010 < P-value < 0.0250.005 < P-value < 0.010P-value < 0.00 Find a 90% confidence interval…A sports writer wants to see if a football filled with helium travels farther, on average, than a football filled with air. 12 footballs were filled with helium to the recommend pressure and 15 footballs were filled with air to the recommended pressure. The mean yardage for the helium filled footballs was 267 yards with a standard deviation of 3 yards. The mean yardage for the air filled footballs was 241 yards with a standard deviation of 5 yards. Assume the populations are normal with equal variances. (a). Construct a 99% confidence interval for the mean difference in in yardage for the two types of footballs Lower bound (use 3 decimal places) Upper bound (use 3 decimal places) (b). What can you conclude about the sports writer's idea that helium footballs travel farther, on average? The helium footballs are no different than the other footballs, on average The other footballs travel farther on average than the helium footballs The helium footballs travel farther on average than the…
- Is this correct?A team of researchers found that age distributions in a population of 100,000 people was not Normal. However, after they took a large number of simple random samples, each with (N=100), they observed that the sampling distribution of mean tended toward Normality. Really? Why is it possible?It currently takes users a mean of 26 minutes to install the most popular computer program made by RodeTech, a software design company. After changes have been made to the program, the company executives want to know if the new mean is now different from 26 minutes so that they can change their advertising accordingly. A simple random sample of 37 new customers are asked to time how long it takes for them to install the software. The sample mean is 27.9 minutes with a standard deviation of 7.7 minutes. Perform a hypothesis test at the 0.05 level of significance to see if the mean installation time has changed. Step 2 of 3: Compute the value of the test statistic. Round your answer to three decimal places.
