TI-Nspire CX II field manual for IB Math
Descriptive stats with frequency table
Enter values in one table column and frequencies in a second column, run one-variable statistics with a frequency list, and read the weighted statistics.
Find the descriptive statistics for the frequency table with values 2, 4, 6, 8 and frequencies 3, 2, 4, 1.
Open a Lists & Spreadsheet page, name the first column x, and enter the values 2, 4, 6, 8. Name the second column f, and enter the matching frequencies 3, 2, 4, 1.
Run one-variable statistics: press → 4: Statistics → 1: Stat Calculations → 1: One-Variable Statistics. Leave Num of Lists: 1 and press , then between the fields to select x as the X1 list and f as the frequency list.
Press to calculate. The Nspire writes the weighted one-variable summary statistics into the spreadsheet.
The calculator gives xˉ=4.6, sx≈2.12, σx≈2.01, and n=10.
Your turn
Work each one on your calculator, then check the answer.
- 1
A frequency table has values 1, 2, 3, 4 with frequencies 5, 8, 4, 3. Find the mean and both standard deviations.
- 2
A frequency table has values 10, 20, 30, 40, 50 with frequencies 2, 5, 8, 4, 1. Find the mean and both standard deviations.
- 3
A frequency table has values 0, 1, 2, 3, 4 with frequencies 6, 10, 7, 4, 3. Find the mean and both standard deviations.