Cellphone Calls Answers.com claims that the mean length of all cell phone conversations in the United States is 3.25 minutes (3 minutes and 15 seconds). Assume that this is correct. and also assume that the standard deviation is 4.2 minutes. a. Describe the shape of the distribution of the length of cell phone conversations in this population. Do you expect it to be approximately Normally distributed right-skewed. or left-skewed? Explain your reasoning. b. Suppose that. using a phone company's records, we randomly sample 100 phone calls. We calculate the mean length from this sample and record the value. We repeat this thousands of times. What will be the (approximate) mean value of the distribution of these thousands of sample means? c. Refer to part b. What will be the standard deviation of this distribution of thousands of sample means?
Cellphone Calls Answers.com claims that the mean length of all cell phone conversations in the United States is 3.25 minutes (3 minutes and 15 seconds). Assume that this is correct. and also assume that the standard deviation is 4.2 minutes. a. Describe the shape of the distribution of the length of cell phone conversations in this population. Do you expect it to be approximately Normally distributed right-skewed. or left-skewed? Explain your reasoning. b. Suppose that. using a phone company's records, we randomly sample 100 phone calls. We calculate the mean length from this sample and record the value. We repeat this thousands of times. What will be the (approximate) mean value of the distribution of these thousands of sample means? c. Refer to part b. What will be the standard deviation of this distribution of thousands of sample means?
Solution Summary: The author explains whether the distribution of the length of cell phone conversations in the population is normal, right-skewed, or left.
Cellphone Calls Answers.com claims that the mean length of all cell phone conversations in the United States is 3.25 minutes (3 minutes and 15 seconds). Assume that this is correct. and also assume that the standard deviation is 4.2 minutes.
a. Describe the shape of the distribution of the length of cell phone conversations in this population. Do you expect it to be approximately Normally distributed right-skewed. or left-skewed? Explain your reasoning.
b. Suppose that. using a phone company's records, we randomly sample 100 phone calls. We calculate the mean length from this sample and record the value. We repeat this thousands of times. What will be the (approximate) mean value of the distribution of these thousands of sample means?
c. Refer to part b. What will be the standard deviation of this distribution of thousands of sample means?
Features Features Normal distribution is characterized by two parameters, mean (µ) and standard deviation (σ). When graphed, the mean represents the center of the bell curve and the graph is perfectly symmetric about the center. The mean, median, and mode are all equal for a normal distribution. The standard deviation measures the data's spread from the center. The higher the standard deviation, the more the data is spread out and the flatter the bell curve looks. Variance is another commonly used measure of the spread of the distribution and is equal to the square of the standard deviation.
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