HP 20B manual 1I1 50I, 2I1 65I, 3I1 60I, 4I1 75I, Statistics Example

Statistical Operations

Table 10-1The Statistics Menu Items

Menu Item	Description
Sigma Y	The sum of the y values.
Sigma X2	The sum of the squares of the x values.
Sigma Y2	The sum of the squares for the y values.
Sigma XY	The sum of the products of the x and y values.

Statistics Example

Sales for the last five months are represented by the pairs of values shown below, with the month number as x, and the sales values as y. Enter these into the Data menu. Using the Statistics menu for Predictions, predict sales for month seven. What is the linear regression line? What is the sum of all the y values? See Tables 10-2 and 10-3.

Table 10-2Months and Sales

Month	Sales Values
1	150
2	165
3	160
4	175
5	170

Table 10-3Statistics Example

Keys Display Description

:y

Opens Data menu.

1I1

50I

Inputs values for X(1) and Y(1).

2I1

65I

Inputs values for X(2) and Y(2).

3I1

60I

Inputs values for X(3) and Y(3).

4I1

75I

Inputs values for X(4) and Y(4).

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