Question

Please answer all questions below

2. For a population with a mean equal to 250 and a standard deviation equal to 25​, calculate the standard error of the mean for the following sample sizes. ​a) 10 ​b) 40 ​c) 70

3. Managers at a local phone service wireless retail center have a goal that 74​% of the​ center's customers will have to wait less than five minutes for service. The data below shows the wait times of a random sample of 25 customers in minutes. Does this sample provide evidence that​ management's goal is being​ achieved? 4.3 5.6 2.4 10.4 3.7 3.6 0.3 7.9 4.7 4.5 4.9 2.3 3.2 9.3 6.8 5.4 4.3 0.3 2.8 5.6 5.9 3.2 2.3 2.7 4.2

4. A college has 250 full-time employees that are currently covered under the​ school's health care plan. The average​ out-of-pocket cost for the employees on the plan is $1,820 with a standard deviation of $515. The college is performing an audit of its health care plan and has randomly selected 30 employees to analyze their​ out-of-pocket costs. a. Calculate the standard error of the mean. b. What is the probability that the sample mean will be less than $1,765​? c. What is the probability that the sample mean will be more than $1,800​? d. What is the probability that the sample mean will be between $1,845 and $1,890​?

5. For a population with a proportion equal to 0.28​, calculate the standard error of the proportion for the following sample sizes. a) 50 b) 100 c)150

Answer 1