Measures of Central Tendency and Z score

A: To revise an existing inventory system, a company needs to know something about the lead time for orders it places for a critical part. The company looks at the last 20 orders placed and finds that the lead time in days are: 1,4,6,7,4,5,6,8,4,5,7,8,4,6,7,10,4,6,7,11.

a-What is the meanlead time for an order?

b-What is the medianlead time for an order?

c-What is the modelead time for an order?

d- What is the standard deviationfor an order?

Prob. B A normal population has a mean of 20.0 and a standard deviation of 4.0.

a-Compute the z-value associated with 25.

b-Compute the z-value associated with 18.

The solution provides step-by-step method for the calculation of central tendency measures, standard deviation and Z score. Formula for the calculation and Interpretations of the results are also included.