Marketing companies have collected data implying that teenage girls use more ring tones on thei cellular phones than teenage boys do. In one particular study of 40 randomly chosen teenage girls and boys (20 of each) with cellular phones, the mean number of ring tones for the girls was 3.4 with a standard deviation of 1.4. The mean for the boys was 1.7 with a standard deviation of 0.7. Conduct a hypothesis test at the 5% level to determine approximately the same or if the girls' mean is higher than the boys' mean. the means are

Marketing companies have collected data implying that teenage girls use more ring tones on thei cellular phones than teenage boys do. In one particular study of 40 randomly chosen teenage girls and boys (20 of each) with cellular phones, the mean number of ring tones for the girls was 3.4 with a standard deviation of 1.4. The mean for the boys was 1.7 with a standard deviation of 0.7. Conduct a hypothesis test at the 5% level to determine approximately the same or if the girls' mean is higher than the boys' mean. the means are

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Description: Marketing companies have collected data implying that teenage girls use more ring tones on theircellular phones than teenage boys do. In one particular study of 40 randomly chosen teenagegirls and boys (20 of each) with cellular phones, the mean num

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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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.
A researcher claims that the stomachs of blue crabs from Location A contain more fish than the stomachs of blue crabs from Location B. The stomach contents of a sample of 14 blue crabs from Location A contain a mean of 194 milligrams of fish and a standard deviation of 37 milligrams. The stomach contents of a sample of 8 blue crabs from Location B contain a mean of 184 milligrams of fish and a standard deviation of 44 milligrams. At a = 0.05, can you support the researcher's claim? Assume the population variances are equal. Complete parts (a) through (d) below. (a) Identify the null and alternative hypotheses. Choose the correct answer below. ОА. Но H1-H2 0 OD. Ho: H₁-12₂=0 Ha H1 H₂0 enough evidence at the 5% level of significance to support the researcher's claim.
A new small business wants to know if its current radio advertising is effective. The owners decide to look at the mean number of customers who make a purchase in the store on days immediately following days when the radio ads are played as compared to the mean for those days following days when no radio advertisements are played. They found that for 10 days following no advertisements, the mean was 18.3 purchasing customers with a standard deviation of 1.8 customers. On 7 days following advertising, the mean was 19.4 purchasing customers with a standard deviation of 1.6 customers. Test the claim, at the 0.02 level, that the mean number of customers who make a purchase in the store is lower for days following no advertising compared to days following advertising. Assume that both populations are approximately normal and that the population variances are equal. Let days following no advertisements be Population 1 and let days following advertising be Population 2. Step 3 of 3: Draw a…
A researcher claims that the stomachs of blue crabs from Location A contain more fish than the stomachs of blue crabs from Location B. The stomach contents of a sample of 13 blue crabs from Location A contain a mean of 191 milligrams of fish and a standard deviation of 37 milligrams. The stomach contents of a sample of 7 blue crabs from Location B contain a mean of 185 milligrams of fish and a standard deviation of 41 milligrams. At α=0.10, can you support the researcher's claim? Assume the population variances are equal and that both samples are from normal populations. Complete parts (a) through (d) below. (a) Identify the null and alternative hypotheses. Choose the correct answer below. A. H0: μ1−μ2=0 Ha: μ1−μ2>0 B. H0: μ1−μ2<0 Ha: μ1−μ2=0 C. H0: μ1−μ2=0 Ha: μ1−μ2≠0 D. H0: μ1−μ2=0 Ha: μ1−μ2<0 (b) Calculate the test statistic t=? (Round to three decimal places as needed.) (c) Calculate the…
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A pharmaceutical company needs to know if its new cholesterol drug, Praxor, is effective at lowering cholesterol levels. It believes that people who take Praxor will average a greater decrease in cholesterol level than people taking a placebo. After the experiment is complete, the researchers find that the 46 participants in the treatment group lowered their cholesterol levels by a mean of 19.5 points with a standard deviation of 4.9 points. The 37 participants in the control group lowered their cholesterol levels by a mean of 18.4 points with a standard deviation of 4.1 points. Assume that the population variances are not equal and test the company's claim at the 0.02 level. Let the treatment group be Population 1 and let the control group be Population 2. Step 2 of 3: Compute the value of the test statistic. Round your answer to three decimal places.
The owners of the Metro Cash & Carry wished to study customers’ shopping habits. From earlier studies, the owners were under the impression that a typical shopper spends 0.7 hour at the mall, with a standard deviation of 0.10 hour. Recently the owners added some specialty restaurants designed to keep shoppers in the mall longer. A research team was hired to evaluate the effects of the restaurants. A sample of 45 shoppers by the team revealed that the mean time spent in the mall had increased to 0.80 hour. i. Develop a hypothesis test to determine if the mean time spent in the mall changed. Use the .10 significance level. ii. Suppose the mean shopping time actually increased from 0.75 hour to 0.79 hours. What is the probability of making a Type II error? iii)When research team reported the information in part (b) to the mall owners, the owners believed that the probability of making a Type II error was too high. How could this probability be reduced? plz sove it…
A custodian wishes to compare two competing floor waxes to decide which one is best. He believes that the mean of WaxWin is less than the mean of WaxCo. In a random sample of 20 floors of WaxWin and 17 of WaxCo. WaxWin had a mean lifetime of 26.4 with a standard deviation of 8.6 and WaxCo had a mean lifetime of 27.2 with a standard deviation of 6.6. Perform a hypothesis test using a significance level of 0.05 to help him decide. Let WaxWin be sample 1 and WaxCo be sample 2 The correct hypotheses are: Ο Ηο: μι < με HA₁₂(claim) Ο Ηρ: με 2 με HA: 1₂(claim) O Ho: ₁ = ₂ HAM12(claim) Since the level of significance is 0.05 the critical value is -1.69 (round to 3 places) The test statistic is: The p-value is: (round to 3 places)
A pharmaceutical company needs to know if its new cholesterol drug, Praxor, is effective at lowering cholesterol levels. It believes that people who take Praxor will average a greater decrease in cholesterol level than people taking a placebo. After the experiment is complete, the researchers find that the 34 participants in the treatment group lowered their cholesterol levels by a mean of 22.2 points with a standard deviation of 3.4 points. The 42 participants in the control group lowered their cholesterol levels by a mean of 21.2 points with a standard deviation of 1.8 points. Assume that the population variances are not equal and test the company's claim at the 0.10 level. Let the treatment group be Population 1 and let the control group be Population 2. Step 1 of 3: State the null and alternative hypotheses for the test. Fill in the blank below. Ho:₁ = ₂ Ha: M •M₂
A new small business wants to know if its current radio advertising is effective. The owners decide to look at the mean number of customers who make a purchase in the store on days immediately following days when the radio ads are played as compared to the mean for those days following days when no radio advertisements are played. They found that for 13 days following no advertisements, the mean was 23.9 purchasing customers with a standard deviation of 1.9 customers. On 6 days following advertising, the mean was 24.7 purchasing customers with a standard deviation of 1.6 customers. Test the claim, at the 0.01 level, that the mean number of customers who make a purchase in the store is lower for days following no advertising compared to days following advertising. Assume that both populations are approximately normal and that the population variances are equal. Let days following no advertisements be Population 1 and let days following advertising be Population 2. Step 3 of 3: Draw a…
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.
A researcher claims that the stomachs of blue crabs from Location A contain more fish than the stomachs of blue crabs from Location B. The stomach contents of a sample of 13 blue crabs from Location A contain a mean of 191 milligrams of fish and a standard deviation of 38 milligrams. The stomach contents of a sample of 8 blue crabs from Location B contain a mean of 189 milligrams of fish and a standard deviation of 44 milligrams. At a = 0.10, can you support the researcher's claim? Assume the population variances are equal. Complete parts (a) through (d) below. t= 0.110 (Round to three decimal places as needed.) (c) Calculate the P-value. P=|| (Round to four decimal places as needed.)