STAT200 Quiz-1 | Complete Solution

STAT200  Quiz-1
covers material for week 1 and week 2.
Show steps of solutions, not just answers.

1.  Let’s say you have a list of all people who work for the company.
Describe how you would select a sample of people from this company using
a) systematic sampling
b) stratified sampling technique.
________________________________________
2.  What’s the difference between Descriptive and Inferential Statistics?
________________________________________
3.  Present following data in Steam and Leaf display:
     32, 54, 28, 22, 18, 65, 44, 31, 52, 48, 32, 35, 37, 45, 33.      
________________________________________
4.  Based on the Box Plots below,

answer the following questions:
a) between what numbers (roughly) are the low 25% of time results for Male?
b) between what numbers (roughly) are the upper 25% of time results for Female?
c) what is the range (roughly) for 50% data in the middle for Male?
________________________________________
5.  Find Median for each of the following number collections:   
    A)  10, 14, 25, 30, 18, 16, 20;     
    B)  23, 12, 34, 44, 30, 50, 55, 60
________________________________________
6. Find Quartiles Q1, Q2 and Q3 and Interquartile Range for the following number collection:
    8, 12, 14, 15, 18, 20, 21, 24, 27, 30, 33, 35
________________________________________
7. Calculate Sample Standard Deviation for the following data collection:
    11, 18, 21, 29, 33, 38
________________________________________
8. Find 90th percentile for the following data collection:
             2, 7, 10, 12, 14, 16, 20, 22, 27, 30, 34, 40, 48, 50, 60.
________________________________________

________________________________________
9. Find percentile for the number 14 in this data collection:
             2, 7, 10, 12, 14, 16, 20, 22, 27, 30, 34, 40, 48, 50, 60.
________________________________________
10. On a timed test, the third quartile Q3 for the time it took to finish the test was 45 minutes.
What does it mean? Interpret the third quartile in the context of this situation.
________________________________________
11. Calculate the Mean for the given Grouped Frequency Table:
Interval    Frequency
10 – 20    4
20 – 30    8
30 – 40    12
40 – 50    10
50 – 60    6

________________________________________
12. What is the difference between Variance and Standard Deviation?
________________________________________