Choose the best answer and justify for full credit. The quality control departme
ID: 3331145 • Letter: C
Question
Choose the best answer and justify for full credit.
The quality control department of a semiconductor manufacturing company tests every 100th product from the assembly line. This type of sampling is called:
(a) cluster
(b) convenience
(c) systematic
(d) stratified
A study was conducted at a local college to analyze the trend of average GPA of all students graduated from the college. According to the Registrar, the average GPA for students with economics major from the class of 2016 is 3.5. The value 3.5 is a
(i) statistic
(ii) parameter
(iii) cannot be determined
The hotel ratings are usually on a scale from 0 star to 5 stars. The level of this measurement is
(i) interval
(ii) nominal
(iii) ordinal
(iv) ratio
600 students took a chemistry test. You sampled 100 students to estimate the average score and the standard deviation. How many degrees of freedom were there in the estimation of the standard deviation?
(i) 599
(ii) 600
(iii) 99
(iv) 100
You choose an alpha level of 0.05 and then analyze your data. What is the probability that you will make a Type I error given that the null hypothesis is true?
(i) 0.01
(ii) 0.025
(iii) 0.05
(iv) 0.10
Explanation / Answer
1) The quality control department of a semiconductor manufacturing company tests every 100th product from the assembly line. This type of sampling is called:
(c) systematic
In systematic sampling, we draw sample from large population. Here we select a starting point randomly and after that sample is drawn at every fixed periodic interval.
2) Here we took sample of economic major from the class of 2016. Hence average taken of this class is called statistic .
Statistic is used to estimate value of population parameter using samples.
3) The hotel ratings are usually on a scale from 0 star to 5 stars.
Here order of scale is important.
The correct option is (iii) ordinal
4) The degrees of freedom used to estimate sample size is n-1. Where n is sample size.
Here sample size =n = 100
Hence degrees of freedom = n-1 = 100 - 1 = 99
Hence correct option is
(iii) 99
5) The level of significance is also called as type I error.
Hence the correct option is (iii) 0.05.