To create a frequency distribution for the estimated distribution of the U.S. population by age for the year 2015, you'll first need to list the age groups and their corresponding midpoints. Then, you'll need to provide the frequency or estimated population for each age group. After that, you can calculate the sample mean and sample standard deviation using the midpoint and frequency values.
Here's a possible frequency distribution table for the data:
Age Group Midpoint (x) Frequency (f)
0-4 years 2.5 [Population Value]
5-9 years 7.5 [Population Value]
10-14 years 12.5 [Population Value]
15-19 years 17.5 [Population Value]
20-24 years 22.5 [Population Value]
25-29 years 27.5 [Population Value]
30-34 years 32.5 [Population Value]
35-39 years 37.5 [Population Value]
40-44 years 42.5 [Population Value]
45-49 years 47.5 [Population Value]
50-54 years 52.5 [Population Value]
55-59 years 57.5 [Population Value]
60-64 years 62.5 [Population Value]
65 years and over 70.0 [Population Value]
You would need to replace "[Population Value]" with the actual estimated population values for each age group.
Once you have the populated frequency distribution table, you can calculate the sample mean and sample standard deviation using standard statistical formulas. If you have the complete data with population values for each age group, I can help you calculate those statistics.