Question 5 An insurance company wants to know if the average speed at which men drive cars is greater than that of women drivers. The company took a random sample of 27 cars driven by men on a highway and found the mean speed to be 72 miles per hour with a standard deviation of 2.2 miles per hour. Another sample of 18 cars driven by women on the same highway gave a mean speed of 68 miles per hour with a standard deviation of 2.5 miles per hour. Assume that the speeds at which all men and all women drive cars on this highway are both normally distributed with equal standard deviation. Use 1% significance level to test the hypothesis that the mean speed of cars driven by all men drivers on this highway is greater than that of cars driven by all women driver. Answer the following questions. Man driver Women driver Mean sample 72 mph 68 mph Sample standard deviation 2.2 mph 2.5 mph Sample size 27 18 Identify the claim and state the H0 and H1. Find the critical value. Calculate the test statistic. Make a decision to reject or fail to reject the H0. Interpret the decision in the context of the original claim.
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Identify the claim and state the H0 and H1. The claim is that the mean speed of cars driven by all men drivers on this highway is greater than that of cars driven by all women drivers. H0: μ_men ≤ μ_women (The mean speed of men drivers is less than or equal to Show more…
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An insurance company wants to know if the average speed at which men drive cars is greater than that of women drivers. The company took a random sample of 25 cars driven by men on a highway and found the mean speed to be 70 miles per hour with a standard deviation of 3.2 miles per hour. Another sample of 16 cars driven by women on the same highway gave a mean speed of 72 miles per hour with a standard deviation of 2.5 miles per hour. Assume that the speeds at which all men and all women drive cars on this highway are both normally distributed with the same population standard deviation. (a) Let μ1μ1 and μ2μ2 be the population means of driving speed by men and women drivers, respectively. Find the point estimate for difference between the mean speeds of men and women drivers. (2 points) (b) Test at the 1% significance level whether the mean speed of cars driven by all men drivers on this highway is greater than that of cars driven by all women drivers. (4 points)
Kari H.
Question 4 A random sample of 226 fish caught out of Cedar Bluff lake was weighed. The mean weight of the sample of fish was 4.67 lbs. The standard deviation of the distribution was .7 lbs. What would be the 99% confidence interval for the mean weight of the fish in Cedar Bluff Lake? 4.462 to 4.712 4.551 to 4.789 4.645 to 4.899 4.688 to 5.004 Question 5 The speed of a random sample of 401 cars driving through Hays on I 44 was measured with a radar. The mean speed of the 401 cars was 73 MPH. The standard deviation of the sample distribution of speeds was 5 MPH. What is the 95% confidence interval for the mean speed of all cars driving through Hays on I 44? 73.79 to 74.21 72.51 to 73.49 71.35 to 74.65 70.06 to 75.09 Question 6 The speed of a random sample of 401 cars driving through Hays on I 44 was measured with a radar. The mean speed of the 401 cars was 73 MPH. The standard deviation of the sample distribution of speeds was 5 MPH. What is the 99% confidence interval for the mean speed of all cars driving through Hays on I 44? 71.16 to 72.83 71.85 to 73.05 72.36 to 73.64 72.85 to 73.25
Madhur L.
1. The manager of a grocery store took a random sample of 100 customers. The avg. length of time it took the customers in the sample to check out was 3.1 minutes with a std. deviation of 0.5 minutes. We want to test to determine whether or not the mean waiting time of all customers is significantly > 3 min. The degrees of freedom for t-distribution is a. 99 b. 100 c. 101 2. The manager of a grocery store took a random sample of 100 customers. The avg. length of time it took the customers in the sample to check out was 3.1 minutes with a std. deviation of 0.5 minutes. We want to test to determine whether or not the mean waiting time of all customers is significantly > 3 min. The p-value is between a. 00.5 to .01 b. .025 to .05 c. .01 to .025 d. .05 to .10 3. In order to estimate the average time spent on the computer terminals per student at a university, data were collected for a sample of 81 business students over a one week period. Assume the population standard deviation is 1.8 hours. With a 0.95 probability, the margin of error is approximately a. 0.39 b. 1.64 c. 0.20 d. 196 4. A random sample of 121 automobiles traveling on an interstate showed an average speed of 65 mph. From past information, it is known that the standard deviation of the population is 22 mph. The standard error of the mean is a. 96.60 b. 22.00 c. 4.24 d. 2.00
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