1.) 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 70 randomly chosen teenage girls andboys (35 of each) with cellular phones, the mean number of ring tones for the girls was 3.2 with astandard deviation of 1.5. The mean for the boys was 1.7 with a standard deviation of 0.8. Conduct ahypothesis test at 1% significance level to determine if the means are the same.2.) Researchers conducted a study at 10% significance level, to find out if there is a difference in the use ofreaders by different age groups. Randomly selected participants were divided into two age groups. Inthe 16 to 29 year-old group, 7% of the 628surveyed use readers, while 11% of the 2,309 participants30years old and older use readers.

Given that Sample sizes n1=35 , n2=35 Sample means X̄1=3.2 , X̄2=1.7 s1 =1.5…

Answered: 1.) Marketing companies have collected…

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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Two researchers conducted a study in which two groups of students were asked to answer 42 trivia questions from a board game. The students in group 1 were asked to spend 5 minutes thinking about what it would mean to be a professor, while the students in group 2 were asked to think about soccer hooligans. These pretest thoughts are a form of priming. The 200 students in group 1 had a mean score of 24.4 with a standard deviation of 3.8, while the 200 students in group 2 had a mean score of 15.7 with a standard deviation of 3. Complete parts (a) and (b) below. (a) Determine the 95% confidence interval for the difference in scores, µ, - H3. Interpret the interval. The lower bound is The upper bound is (Round to three decimal places as needed.)
2) A job placement director claims that the average starting salary for nurse is $26000. A sample of 18 nurses has a mean salary of $25620 and a standard deviation of $680. Is there enough evidence to reject the directors claim at a = 5% LOS?
The Chartered Financial Analyst (CFA) designation is fast becoming a requirement for serious investment professionals. Although it requires a successful completion of three levels of grueling exams, it also entails promising careers with lucrative salaries. A student of finance is curious about the average salary of a CFA charterholder. He takes a random sample of 36 recent charterholders and computes a mean salary of $129,000 with a standard deviation of $22,000. Use this sample information to determine the 99% confidence interval for the average salary of a CFA charterholder. (You may find it useful to reference the t table. Round final answers to the nearest whole number.) Confidence interval
A study was done to look at the relationship between number of partners college students have had in their lifetimes and their GPAs. The results of the survey are shown below. Partners 7 8 6 1 6 6 4 GPA 1.4 1.5 1.4 3 2.3 1.5 2.9 Find the correlation coefficient: r=r= Round to 2 decimal places. The null and alternative hypotheses for correlation are:H0:H0: ? r ρ μ Incorrect == 0 Ha:Ha: ? r ρ μ Incorrect ≠≠ 0 Use a level of significance of α=0.05α=0.05 to state the conclusion of the hypothesis test in the context of the study. You may want to reference the 95% Critical Values of the Sample Correlation Coefficient. There is statistically insignificant evidence to conclude that there is a correlation between the number of partners students have had in their lifetimes and their GPA. Thus, the use of the regression line is not appropriate. There is statistically significant evidence to conclude that a student who has had more partners will have a lower GPA than a…
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.
An economist is studying salaries for high technology companies and wants to test the claim that the average salary for high tech employees is less than $70,000. The economist selects a sample of 35 random employees from various high tech companies and records their salaries. Based on past studies, the economist determines that the population standard deviation is $8,500. The economist conducts a one-mean hypothesis test at the 5% significance level to test the claim that the average salary for high tech employees is less than $70,000. Which is the correct setup for the null and alternative hypothesis for this example? Select the correct answer below: H0:μ=70,000; Ha:μ<70,000, which is a left-tailed test. H0:μ=70,000; Ha:μ>70,000, which is a right-tailed test H0:μ<70,000; Ha:μ=70,000, which is a left-tailed test. H0:μ>70,000; Ha:μ=70,000, which is a left-tailed test.
A custodian wishes to compare two competing floor waxes to decide which one is best. He believes that the mean of WaxWin is not equal to the mean of WaxCo. In a random sample of 12 floors of WaxWin and 20 of WaxCo. WaxWin had a mean lifetime of 27.6 with a standard deviation of 8.8 and WaxCo had a mean lifetime of 20.3 with a standard deviation of 7.6. Perform a hypothesis test using a significance level of 0.01 to help him decide. Let WaxWin be sample 1 and WaxCo be sample 2 The correct hypotheses are: HA: P1 > µ2(claim) Ho: µ1 2 µ2 HA: µ1 < µ2(claim) Ho: µ1 = µ2 HA: H1 + H2(claim) Since the level of significance is 0.01 the critical value is 2.836 and -2.836 The test statistic is: (round to 3 places) The p-value is: (round to 3 places)
10
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 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.
Two researchers conducted a study in which two groups of students were asked to answer 42 trivia questions from a board game. The students in group 1 were asked to spend 5 minutes thinking about what it would mean to be a professor, while the students in group 2 were asked to think about soccer hooligans. These pretest thoughts are a form of priming. The 200 students in group 1 had a mean score of 26.3 with a standard deviation of 5.2, while the 200 students in group 2 had a mean score of 17.6 with a standard deviation of 2.8. Complete parts (a) and (b) below. (a) Determine the 90% confidence interval for the difference in scores, μ1−μ2. Interpret the interval. The lower bound is nothing. The upper bound is nothing. (Round to three decimal places as needed.)

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