Question

The scores of four roommates on the Law School Admission Test (LSAT) are:

628 593 455 503




Find the mean, the standard deviation, and the standard error of the mean. Is it appropriate to calculate a confidence interval for these data? Explain why or why not.

Answer 1

Explanation:

The given scores are 628 593 455 503

Mean = sum of scores/number of scores

Mean = (628 + 593 + 455 + 503)/4

Mean = 544.75

Standard deviation = √summation(x - mean)/n

Summation x - mean =

(628 - 544.75)^2 + (593 - 544.75)^2 + (455 - 544.75)^2 + (503 - 544.75)^2 = 19056.75

n = 4

Standard deviation = √(19056.75/4) = √4764.1875

= 60.02

The standard error of the mean = standard deviation/√n

Standard error = 60.02/√4 = 30.01

it is inappropriate to calculate a confidence interval for these data. This is because confidence interval is usually calculated for an unknown population parameter. From the data given, the population parameters are already known