question archive 1) What is the probability that the score on a normally distributed variable is in each of the following areas? a
1) What is the probability that the score on a normally distributed variable is in each of the following areas? a
Subject:StatisticsPrice:12.86 Bought3
1) What is the probability that the score on a normally distributed variable is in each of the following areas? a. Between the mean and z=.45 b. Between the mean and z= -1.80 C. Beyond (less than) z= -95 2. Recall from lecture that the number of hours people sleep is a normally distributed variable. The mean is 7.5 hours and the standard deviation is 1.25 hours. a. What proportion of people sleep between 7 and 9 hours a night? b. What proportion of people sleep more than 6 hours a night? 3. What is a sampling distribution? 4. In a Psy 320 class (N=50) the number of close friends people reported having had a mean of 4.76, and a standard deviation of 4.77. a. What is the standard error of the mean, as calculated from the sample? b. Place a 95% confidence interval around the mean. c. Interpret what this confidence interval tells us. d. What are two ways to decrease the size of a confidence interval? Why would we want to do this? 5. If the population mean number of friends was 4.10, and standard deviation 2.46, what is the likelihood that the sample mean of 4.76 (or higher) would be obtained from this population?
