HP 10bII+ Financial j\W, g\W, \Z\«, D:::\Z

Table 12-10 Example for forecasting

Keys	Display	Description
\Z\«	0.90	Calculates correlation
		coefficient.

Estimate what the level of sales would be if the business purchased 7 or 8 minutes of advertising.

Table 12-11	Estimating the level of sales
Keys		Display	Description
j\W		3,357.38	Estimates sales if 7 minutes of
			advertising were purchased.
g\W		3,783.25	Estimates sales if 8 minutes were
			purchased.

How many minutes of advertising should Ali’s buy to attain sales of 3,000?

Table 12-12	Estimating the minutes of advertising for 3,000 sales
Keys		Display	Description
D:::\Z			required for 3,000 in sales.
		6.16	Estimates minutes of advertising

Weighted Mean

The following procedure calculates the weighted mean of data points x1, x2, …, xn occurring with weights y1, y2, …, yn.

1.Use Æand ¡to enter x,y pairs. The y-values are the weights of the x-values.

2.Press \T.

Example 5

A survey of 266 one-bedroom rental apartments reveals that 54 of them rent for 500 per month, 32 for 505, 88 for 510, and 92 for 516. What is the average monthly rent?

124 Statistical Calculations