The average weight of the entire batch of the boxes of cereal filled today was 20.15 ounces. A random sample of four boxes was selected with the following weights: 20.05, 20.56, 20.72, and 20.43. The sampling error for this sample is _______.

According to the National Retail Federation, men spent an average of $484 over a recent Black Friday weekend. Assume that the standard deviation for this population is $146. A random sample of 42 men shoppers over this weekend was selected. What is the probability that the average amount spent on Black Friday weekend from this sample was less than $500?

(round your answer to 2 decimal points)

According to the National Retail Federation, women spent an average of $317 over a recent Black Friday weekend. Assume that the standard deviation for this population is $90. A random sample of 50 women shoppers over this weekend was selected. What is the probability that the average amount spent on Black Friday weekend from this sample was more than $300?

(round your answer to 2 decimal places)

According to the Labor Department, the average duration of unemployment for adults ages 20 to 24 was 34.6 weeks during a recent month. Assume that the standard deviation for this population is 10.2 weeks. A random sample of 36 adults in this age group was selected. What is the probability that the average duration of unemployment was between 31 and 35 weeks?

(round your answer to 4 decimal places)