As mentioned earlier, standard deviation tells us how far numbers in a set are spread out from their mean. Let's compare two datasets, presented in two histograms below.
For the first histogram, the mean is equal to 0 and the standard deviation equals approximately 2.22. For the second histogram, the mean and the standard deviation are equal to 0 and approximately 4.73, respectively. Notice that while the means for these two datasets are the same, the standard deviations differ greatly. The data represented by the second histogram—with greater standard deviation—are spread farther from the mean, whereas the data from the first dataset are all clustered together near the mean.
Look at the following two datasets and decide which contains elements that are more spread out. Your answer should be based on the values of the standard deviation. (Write A or B.)
A = {-2, -3, -5, 0, 9, 3, 5, 6}
B = {-100, 1, 2, 3, 1, 2, 3}
Answer :
Compare the monthly salaries (in $) in two companies. Look at the following tables, and answer the questions below. (Round your answers to two decimal places.)
COMPANY A
| Salary | Number of people with this salary |
|---|---|
| 3500 | 8 |
| 4200 | 5 |
| 4500 | 5 |
| 4900 | 2 |
COMPANY B
| Salary | Number of people with this salary |
|---|---|
| 3800 | 2 |
| 4100 | 3 |
| 4300 | 5 |
| 4500 | 6 |
| 4700 | 8 |
Calculate the mean of the salaries in each company.
Company A:
Company B:
Calculate the standard deviation of the salaries in each company.
Company A:
Company B:
Which company pays better on average? (Write A or B.)
Answer :
Which company has smaller gap between the salaries?
Answer :
