(5)A statistician of a small criminal justice program wanted to estimate the average number ofbooks required by instructors. Using bookstore data, he drew a random sample of 30courses and obtained a sample mean of 1.8 books and a sample standard deviation of (0.4).Construct a 99% confidence interval to estimate the mean number of books assigned byinstructors on campus.

Here n = 30, Sample mean = x-bar = 1.8, Sample SD = s = 0.4 years Now since Population SD is not…

Answered: (5) A statistician of a small criminal…

MATLAB: An Introduction with Applications

6th Edition

ISBN:9781119256830

Author:Amos Gilat

Publisher:Amos Gilat

Chapter1: Starting With Matlab

Section: Chapter Questions

Problem 1P

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For a new study conducted by a fitness magazine, 280 females were randomly selected. For each, the mean daily calorie consumption was calculated for a September-February period. A second sample of 240 females was chosen independently of the first. For each of them, the mean daily calorie consumption was calculated for a March-August period. During the September-February period, participants consumed a mean of 2385.7 calories daily with a standard deviation of 210. During the March-August period, participants consumed a mean of 2414.3 calories daily with a standard deviation of 285. The population standard deviations of daily calories consumed for females in the two periods can be estimated using the sample standard deviations, as the samples that were used to compute them were quite large. Construct a 90% confidence interval for u, -u,, the difference between the mean daily calorie consumption u, of females in September-February and the mean daily calorie consumption u, of females in…
Researchers from a certain country were interested in how characteristics of the spleen of residents in their tropical environment compare to those found elsewhere in the world. The researchers randomly sampled 93 males and 107 females in their country. The mean and standard deviation of the spleen lengths for the males were 10.8 cm and 0.9 cm, respectively, and those for the females were 10.2 cm and 0.7 cm, respectively. At the 5% significance level, do the data provide sufficient evidence to conclude that a difference exists in the mean spleen lengths of males and females in the country? Click here to view page 1 of the table of critical values of t. Click here to view page 2 of the table of critical values of t. O E. Ho: H1 H₂ Hai Hg = H2 Compute the test statistic. =(Round to two decimal places as needed.) Determine the critical value(s). t= OF. Ho: H1 H₂ Ha: H1 H₂ 0 (Round to three decimal places as needed. Use a comma to separate answers as needed.) What is the conclusion of the…
#21)
The principal at a large high school claims that students spend at least 10 hours per week doing homework, on average. To investigate this claim, an AP Statistics class selected a random sample of 250 students from their school and asked them how long they spent doing homework during the last week. The sample mean was 10.2 hours and the sample standard deviation was 4.2 hours. Construct and interpret a 95% confidence interval for the mean time that students at this school spent doing homework in the last week. Based on your interval, what can you conclude about the principal's claim? What is your t* value? Remember to use the conservative DF value.
You were told that the mean daily cost of a hotel room in downtown St. Louis is $120. You will be needing to rent a hotel room there in the near future and you want to find the best rate. You randomly select a sample of 18 hotel rooms and find that the average cost is $121.33 with a standard deviation of $18.046. At the α = 0.05 significance level, determine if there is enough evidence to reject the claim. What is the decision for this hypothesis test? You were told that the mean daily cost of a hotel room in downtown St. Louis is $120. You will be needing to rent a hotel room there in the near future and you want to find the best rate. You randomly select a sample of 18 hotel rooms and find that the average cost is $121.33 with a standard deviation of $18.046. At the α = 0.05 significance level, determine if there is enough evidence to reject the claim. What is the decision for this hypothesis test? Reject the null because the test statistic is in the critical region and the…
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Statistics Question
A technician compares repair costs for two types of microwave ovens (type I and type II). He believes that the repair cost for type I ovens is greater than the repair cost for type II ovens. A sample of 35 type I ovens has a mean repair cost of $80.39. The population standard deviation for the repair of type I ovens is known to be $24.63. A sample of 31 type II ovens has a mean repair cost of $73.47. The population standard deviation for the repair of type II ovens is known to be $10.42. Conduct a hypothesis test of the technician's claim at the 0.05 level of significance. Let i be the true mean repair cost for type I ovens and µz be the true mean repair cost for type II ovens. Step 1 of 5: State the null and alternative hypotheses for the test.
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A research article reported that for a random sample of 850 meal purchases made at fast food chain A, the mean number of calories was 1,004, and the standard deviation was 489. For a random sample of 2,108 meal purchases made at fast food chain B, the mean number of calories was 905, and the standard deviation was 622. Based on these samples, is there convincing evidence that the mean number of calories in fast food chain B meal purchases is less than the mean number of calories in fast food chain A meal purchases? (Test the relevant hypotheses using a 0.05 level of significance. Use ?1 for fast food chain B and ?2 for fast food chain A.) State the appropriate null and alternative hypotheses. Find the test statistic and P-value. (Use SALT. Round your test statistic to one decimal place and your P-value to three decimal places.) t= P-value= State the conclusion in the problem context. We fail to reject H0. There is convincing evidence that the mean number of calories in fast food…

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