IQ scores among the general population have a mean of 100 and a standard deviation of 15. A researcher claims that the standard deviation, o, of IQ scores for males is less than 15. A random sample of 19 IQ scores for males had a mean of 101 and a standard deviation of 10. Assuming that IQ scores for males are approximately normally distributed, is there significant evidence (at the 0.05 level of significance) to conclude that the researcher's claim is correct? Perform a one-tailed test. Then complete the parts below. Carry your intermediate computations to three or more decimal places and round your answers as specified below. (If necessary, consult a list of formulas.) (a) State the null hypothesis H, and the alternative hypothesis H,. H, :0 H :0 (b) Determine the type of test statistic to use. (Choose one) ▼ D=0 OSO (c) Find the value of the test statistic. (Round to three or more decimal places.) O

The mean score on a driving exam for a group of driver’s education students is 76 points, with a standard deviation of 6 points. Apply chebychev’s theorem to the data using K=2. Interpret, At least ___% of the exam score falls between ___and ____

The average American consumes 89 liters of alcohol per year. Does the average college student consume less alcohol per year? A researcher surveyed 15 randomly selected college students and found that they averaged 87.3 liters of alcohol consumed per year with a standard deviation of 15 liters. What can be concluded at the the a = 0.05 level of significance? a. For this study, we should use Select an answer b. The null and alternative hypotheses would be: Но: ? Select an answer V Н: ? v Select an answer V c. The test statistic ? v = (please show your answer to 3 decimal places.) d. The p-value = (Please show your answer to 4 decimal places.) e. The p-value is ? v a f. Based on this, we should Select an answer g. Thus, the final conclusion is that ... the null hypothesis. O The data suggest the population mean is not significantly less than 89 at a = 0.05, so there is statistically insignificant evidence to conclude that the population mean amount of alcohol consumed by college students…

A report states that the mean yearly salary offer for students graduating with a degree in accounting is $48,722. Suppose that a random sample of 50 accounting graduates at a large university who received job offers resulted in a mean offer of $49,870 and a standard deviation of $3900. Do the sample data provide strong support for the claim that the mean salary offer for accounting graduates of this university is higher than the national average of $48,722? Ho: μ = Ha: (Put in the correct symbol and value) ✓ Select an answer a not = P-value: = ↑ Based on the above we choose to Select an answer Question Help: Post to forum Submit Question

The mean number of English courses taken in a two-year time period by male and female college students is believed to be about the same. An experiment is conducted and data are collected from 29 males and 16 females. The males took an average of three English courses with a standard deviation of 0.8. The females took an average of four English courses with a standard deviation of 1.0. Are the means statistically the same? (Assume a 5% level of significance.)

Pilots who cannot maintain regular sleep hours due to their work schedule often suffer from insomnia. A recent study on sleeping patterns of pilots focused on quantifying deviations from regular sleep hours. A random sample of 28 commercial airline pilots was interviewed, and the pilots in the sample reported the time at which they went to sleep on their most recent working day. The study gave the sample mean and standard deviation of the times reported by pilots, with these times measured in hours after midnight. (Thus, if the pilot reported going to sleep at p.m., the measurement was -1.) The sample mean was 0.8 hours, and the standard deviation was 1.6 hours. Assume that the sample is drawn from a normally distributed population. Find a 90% confidence interval for the population standard deviation, that is, the standard deviation of the time (hours after midnight) at which pilots go to sleep on their work days. Then give its lower limit and upper limit.

A researcher claimed that for people that smoke cigarettes, the average number of cigarettes smoked per day is greater than 9. To test her claim, she selected a random sample of 36 smokers and found the mean number of cigarettes smoked per day was 10. The standard deviation of the population is 2.5 cigarettes. At a = 0.05, conduct all steps of a hypothesis test to test the researcher's claim.

In a study of birth order and intelligence, IQ tests were given to 18- and 19-year-old men to estimate the size of the difference, if any, between the mean IQs of firstborn sons and secondborn sons. The following data for 10 firstborn sons and 10 secondborn sons are consistent with the means and standard deviations reported in the article. It is reasonable to assume that the samples come from populations that are approximately normal. Can you conclude that the mean IQ of firstborn sons is greater than the mean IQ of secondborn sons? Let μ1 denote the mean IQ of firstborn sons and μ2 denote the mean IQ of secondborn sons. Use the α = 0.01 level and the P-value method with the table. Firstborn 128 101 128 112 121 105 122 98 106 108 Secondborn 121 125 110 107 114 93 80 94 91 83 Part(a): State the appropriate null and alternate hypotheses. H0:   H1: This is a _____…

In one city, the average amount of time that tenth-graders spend watching television each week is 23 hours. The principal of Birchwood High School believes it is less for the 10th grade students that at his school.  For a sample of 95 tenth-graders from the school, the mean amount of time spent watching television per week was 21.9 hours.  Assuming a population standard deviation of 3.1 hours, does the data provide sufficient evidence to conclude that for all tenth-graders at Birchwood High school, the mean amount of time spent watching television per week is less than the city average of 23 hours?  Perform the appropriate hypothesis test using a significance level of 0.005.  What are the hypotheses?         What is the test statistic? Is it a z or a t?         Find the P-value for this test statistic. How does it compare to the significance level?  On the normal curve, indicate the location of the test statistic  and  the p-value. (label them on the graph)                 Write…

A researcher is conducting a study to determine the mean trough dosage of medication for a population. Assume a previous study was conducted for the same medication and the mean trough dose was found to be 490 mg with a standard deviation of 30 mg. If the researcher wants to be 95% confident the true mean trough dosage of the medication is within 10 mg of the true mean trough dosage, what sample size is needed if the study is predicted to have an 76% retention rate? n = 50 n = 71 n = 47 n = 104