Assignment:
Q1: A Company surveys 32 randomly selected employees and ask the number spent working at home after hours during a week. The results as shown below:
|
10
|
5
|
0
|
8
|
|
0
|
3
|
4
|
4
|
|
2
|
3
|
8
|
1
|
|
4
|
1
|
7
|
5
|
|
7
|
6
|
2
|
1
|
|
0
|
5
|
7
|
5
|
|
10
|
5
|
3
|
6
|
|
6
|
2
|
2
|
3
|
Using Excel, construct a 90% confidence interval for the mean hours worked.
Q2: The weights (in ounces) of 12 randomly sampled cakes as shown in the table below.
|
17
|
10
|
15
|
14
|
|
16
|
12
|
16
|
13
|
|
20
|
11
|
17
|
18
|
Using Excel, constructed a 98% confidence interval using a t-distribution for the mean weight.
Q3: In a survey of 942 musicians, 715 said they began playing an instrument while in elementary school.
Using Excel, construct a 90% confidence interval for the proportion of the musicians who began playing an instrument while in elementary school.
Q4: A restaurant wants to estimate the average number of customer who ask for refills on coffee. They want to be within 5 of the true mean when using a confidence interval of 99%. The standard deviation is estimated at 30.
How many customers must they sample?
Q5: A community wants to estimate the proportion of residents who are pet owners. They want to be within 8% of the true proportion when using a confidence interval of 90%.
How many residents must be sampled if no preliminary estimate is available?
Remember when calculation a sample size, we need to round up to the next whole number (not to the closest whole number) if needed.
Attachment:- Distribution chart.rar