Question

You are the manufacturer of a product used in the aerospace industry. One of the raw materials you obtain from your suppliers is iron bars. Yesterday you got a shipment of 100 iron bars. You have to measure the masses of the iron bars and make a decision as to whether or not they are in the acceptable range or not. To do that you randomly select 10 bars; their masses are 40.0, 39.1, 39.8, 40.2, 40.1, 30.5, 40.0, 38.8, 41.0, 40.2 kg (sample 1). To be confident about the analysis one of your colleagues also randomly selects 10 bars and finds weights of 41.2, 40.3, 40.5, 39.8, 40.5, 40.8, 39.5, 40.5, 41.0, 39.9 kg (sample ).

Question 2a: What is the population mean for the mass of the iron bars received?

Group of answer choices

39

38.97

Not enough information to determine

40

Question 2b: What is the sample standard deviation for the mass of the iron bars received for sample 1 (round to 2 decimal places)?

Question 2c: What is the sample variance for the mass of the iron bars received for sample 2 ((round to 2 decimal places)?

Question 2d: What is the median for the mass of the iron bars received for sample 2?

Question 2e: What is(are) the mode(s) for the mass of the iron bars received for sample 1?

Group of answer choices

39.8

40.0

40.2

40.1

Answer 1

2.a) There is nor enough information to determine the population mean. Though you can make inference by calculation the sample mean

option C is right

b-e)