Dawnbridge

TI-84 Plus CE field manual for IB Math

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18

Descriptive stats with frequency table

All courses

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.

Goal

Find the descriptive statistics for the frequency table with values ​2,4,6,8​ and frequencies ​3,2,4,1.

1

Open the list editor: press and choose 1: Edit.

2

Enter the values in L1: 2, 4, 6, 8. Enter the matching frequencies in L2: 3, 2, 4, 1. Press after each entry.

3

Run one-variable statistics with frequencies: press , move to CALC, choose 1-Var Stats, set List = L1 (type L1 with ) and FreqList = L2 (type L2 with ), then choose Calculate.

NORMALFLOATAUTOREALRADIANMP
1-Var Stats
x̄=4.6
Σx=46
Σx²=252
Sx=2.118699811
σx=2.009975124
n=10
minX=2
Q1=2
Med=5
Q3=6
maxX=8
Result

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. 1

    A frequency table has values ​1,2,3,4​ with frequencies ​5,8,4,3. Find the mean and both standard deviations.

  2. 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. 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.