3. Age of runners. The average of the runners’ ages is µ = 34.05 years with...
3. Age of runners. The average of the runners’ ages is µ = 34.05 years with a standard deviation of σ = 9.83. A simple random sample of 100 runners is taken. a. Find the standard deviation of the sample mean, σx. b. In your opinion, would you be surprised to get a sample (of size 100) with an average age of 36 years? Why or why not? (One idea: start by calculated this probability, the probability of getting an average of 36 years, or more, for a sample of 100 runners.) c. Which number would you trust more: a statistic from a sample with 100 observations or a statistic from a sample with 400 observations? Why?
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3. Age of runners. The average of the runners’ ages is µ = 34.05
years with...
Ages of Proofreaders At a large publishing company, the mean age of proofreaders is 36.2 years...
Ages of Proofreaders At a large publishing company, the mean age of proofreaders is 36.2 years and the standard deviation is 3.7 years. Assume the variable is normally distributed. a. What percentage of the company's proofreaders are between 36 and 37.5 years old? b. If a random sample of 15 proofreaders is selected, find the probability that the mean age of the proofreaders in the sample will be between 36 and 37.5 years.
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The average age of a vehicle registered in the United States is 8 years (96 months)....
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the average age for teachers was 54 years. with younger teachers coming into the industry and...
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Ages of Proofreaders At a large publishing company, the mean age of proofreaders is 36.2 years and the standard deviation is 3.7 years. Assume the variable is normally distributed. a. What percentage of the company's proofreaders are between 36 and 37.5 years old? b. If a random sample of 15 proofreaders is selected, find the probability that the mean age of the proofreaders in the sample will be between 36 and 37.5 years.
D Question 25 4 pts The average age of online consumers a few years ago was 23.3 years. As older individuals gain confidence and trust in theinternet, it is believed that the average age has increased. To test this belief, we selected a random sample of 40 individuals who have made an online purchase this year. The online shoppers in our sample had an average age of 25.2 years, with a standard deviation of 5.3 years. The P-value associated with...
The average age at which adolescent girls reach their adult height is 16 years. Suppose you have a sample of 29 adolescent girls who are developmentally delayed, and who have an average age at which they reached their adult height of 17.8 years and a sample variance of 77.4 years. You want to test the hypothesis that adolescent girls who are developmentally delayed have a different age at which they reached their adult height than all adolescent girls. Calculate the...
The average age of a vehicle registered in the United States is 8 years (96 months). the ages are normally distributed with a standard deviation of 16 months. Assume 7. a car is selected randomly, what is the probabilty that its age is between 91 and 102 months? b. If a random sample of 36 vehicles is taken, what is the probability that the mean of their ages is between 91 and 102 months? 8. (Check your homework notes). In...
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