Statistics Question Help? please

Posted on 2014-04-04 06:28:00 in Statistics by RIHANA

1. A survey of 2500 prospective brides found that 60% of them spent less that $750 on their wedding gown. Use a 0.01 significance level to test the claim that less than 62% of brides spend less than $750 on their wedding gown. How are the results effected if it is learned that the responses were obtained from magazine readers who decided to respond to the survey through and Internet Web site.



2. There are complaints that a bottling company was cheating customers by putting less than 12oz of root beer in its cans. When 24 cans are randomly selected and measured the amounts are found to have a mean of 11.4 oz and a standard deviation of 0.62oz.Tthe company president claims that the sample is too small to be meaningful. Test the claim that consumers are being cheated. Does the company presidents argument have any validity?





3. IQ scores are normally distributed with a mean of 100 and a standard deviation of 15. A simple random sample of 13 statistics professors yields a standard deviation of S = 7.2 A psychologist is quite sure that statistic professors have IQ scores that have a mean greater than 100. He doesn’t understand the concept of standard deviation very well and does not realize that the standard deviation should be lower that 15. Instead, he claims that the statistic professors have IQ scores with a standard deviation equal to 15, the same standard deviation for the general population. Assume that IQ scores of statistic professors are normally distributed and use a 0.05 significance level to test the claim that standard deviation = 15. Based on the result, what do you conclude about the standard deviation of IQ scores for statistic professors?



4. A pre med student in a statistics class is required to do a class project. Intrigued by the body temperatures in a data set she plans to collect her own sample data to test the claim that the mean body temperature is less that 98.6F as is commonly believed. Because of time constraints she only collects data from 12 people. Use a 0.05 significance level to test the claim that these body temperatures come from a population with a mean that is less than 98.6F



98.0 97.5 98.6 98.8 98.0 98.5 98.6 99.4 98.4 98.7 98.6 97.6





5. Some professional baseball players complained that umpires were calling more strikes than the average rate of 61% called the previous year. At one point in the season, umpire Dan Morrison called strikes in 2231 of 3581 pitches. Use a 0.05 significance level to test the claim that his strike rate is greater than 61%.

---

Answer Comment

No Answers Posted Yet.