An attorney claims that more than 25% of all lawyers advertise. A random sample of 200...
An attorney claims that more than 25% of lawyers advertise their services. A sample of 200 lawyers in a certain city showed that 63 had used some form of advertising a. At a 0.05, is there enough evidence to support the attorneys claim? Sample information 2 points Hypothesis information Ho: на: Test statistics p-value Conclusion: 3 points 3 points 3 points 3 points b. Find a 95% confidence interval for the true proportion of attorneys who advertise. Error Bound Calculation...
2. One Sample t-test for Population Mean A vendor claims that the average weight of a shipment of parts is 1.84. The customer randomly chooses 64 parts and finds the sample has an average of 1.88 and standard deviation of 0.03. Should the customer reject the lot? Assume the customer wants to be 95% confident that the supplier's claim is incorrect before he rejects. (This is the same as the last example, except that 0.03 is the sample standard deviation...
Garrison Keller claims the children of Lake Wobegon are above average. You take a simple random sample of 9 children from Lake Wobegon and measure their intelligence with a Wechsler test and find the following scores: {116, 128, 125, 119, 89, 99, 105, 116, and 118}. The mean of this sample (? ̅) is 112.8. We know Wechsler scores are scaled to be normally distributed with a mean of 100 and standard deviation of 15. Is this sample mean sufficiently...
Newborn babies are more likely to be boys than girls. A random sample found that the sample proportion of boys was 0.57 among 3074 newborn children. Is this sample evidence that the birth of boys is more common than the birth of girls in the entire population? Here, we want to test H0: LaTeX: p=0.5 p = 0.5 vs. H1: LaTeX: p>0.5 p > 0.5 . What is the value of the z test statistic for these data? Round your...
A cereal company claims that mean weight of cereal boxes is at most 16.1 ounces. Suppose that a plant manager wishes to test whether the true mean weight of cereal boxes is greater than 16.1 ounces. Suppose that for this problem the population standard deviation is 0.4 and the population distribution is normal. The manager obtain a random sample of size 25 and finds a mean of 16.3 ounces. Using p value approach test the claim of company at significance...
Forty refrigerators from two different models of a refrigerator manufacturer are compared to see if the smaller model uses less energy than the larger model. The energy was measured in kilowatt hours per month (kwh/mo). From years of testing these models, it is known that the standard deviation of kwh/mo is 34 kwh/mo for the smaller model and 40 kwh/mo for the larger one. From this survey, the sample means and standard deviations are 125 and 34, and 90 and...
A random sample of 64 bags of white cheddar popcorn weighed, on average, 5.45 ounces with a standard deviation of 0.25 ounce. Test the null hypothesis that μ=5.5 ounces against the alternative hypothesis, μ<5.5 ounces, at the 0.05 level of significance. What is the p-value? a. 0.025 b. 0.05 c. 0.0548 d. 0.0274
Pg 417 6.47 For a hypothesis test H0: p = 0.3 Ha: p < 0.3 a random sample of size n 200 is taken and the sample proportion p = 0.21 (a) Determine whether it is appropriate to use the normal distribution to estimate the p-value. (b) If it is appropriate to use a normal distribution, complete the test for a significance level of 5% Pg 418 6.55 Home Field in Baseball 2009 There were 2430 Major League Baseball games played in 2009, and the home team won the...
November 6, 2012 was election day. Many of the major television networks aired coverage of the incoming election results during the primetime hours. For a random sample of 25 U.S. adults, the average time spent watching election coverage was 80.44 minutes with standard deviation of 43.99 minutes. We want to do a hypothesis test to see if this is sufficient evidence to reject the null hypothesis in favor of the alternative: H0: the mean number of minutes watching election coverage...
A random sample of 49 measurements from a population with population standard deviation o 3 had a sample mean of x, 9. An independeent random sample of sample mean of x, 11. Test the claim that the population means are 64 measurements from a second population with population standard deviation a2 4 had different. Use level of significance 0.01. (a) What distribution does the sample test statistic follow? Explain. The student's t. We assume that both population distributions are approximately...