Question

1. Suppose the amount of money UCLA students spend on movies during a one month period observes normal distribution. A sample is taken containing monthly movie spending in dollars for several UCLA students as 66.72, 50.23, 40.57, 45.53, 60.45, 70.85, 57.49, and 53.46. Round your numbers to two decimal places. All the calculation should be preceded with the formula used. a. Calculate the sample mean, sample standard deviation, and standard error.  

Answer 1

1. Sample mean is

Create the following table.

data	data-mean	(data - mean)2
66.72	11.0575	122.26830625
50.23	-5.4325	29.51205625
40.57	-15.0925	227.78355625
45.53	-10.1325	102.66755625
60.45	4.7875	22.92015625
70.85	15.1875	230.66015625
57.49	1.8275	3.33975625
53.46	-2.2025	4.85100625

Find the sum of numbers in the last column to get.

So standard deviation is

Standard error is