Hp 20B User Manual download pdf (Page 63)

Statistical Operations

Table 10-1 The Statistics Menu Items

Menu Item Description

Sigma Y The sum of the y values.

Sigma X

The sum of the squares of the x values.

Sigma Y

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 10-2 Months and Sales

Month Sales Values

1 150

2 165

3 160

4 175

5 170

Table 10-3 Statistics Example

Keys Display Description

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).

1 2 ... 58 59 60 61 62 63 64 65 66 67 68 ... 74 75

No comments

Hp 20B User Manual Page 63