levels of the Tower of Pisa (which was leaning even then) and timed its descent by counting his pulse. The following data are measurements Galileo might have made.

t (pulses)

2

2.5

3.5

4

4.5

h (feet)

30

50

90

130

150

Find the power curve formulas that best expresses h as a function of t (h =

AtB).

 

Keystrokes

Display

 

 

CLEAR

 

 

30

 

1.00

First pair data input.

 

 

 

2

 

 

 

50

 

2.00

Second pair data input.

 

 

2.5

 

 

 

90

 

3.00

Third pair data input.

 

 

3.5

 

 

 

130

 

4.00

Fourth pair data input.

 

 

4

 

 

 

150

 

5.00

Fifth pair data input.

 

 

4.5

 

 

 

 

 

1.00

Correlation coefficient (between In

 

 

y and ln x).

 

 

 

0

 

7.72

Value of A.

 

 

 

1

0

1.99

Value of B.

 

 

 

 

 

 

The formula that best expresses h as a function of t is

h= 7.72t1.99

We know, as Galileo did not, that in fact h is proportional to t2.

Standard Error of the Mean

The standard error of the mean is a measure of how reliable the mean of a sample (X) is as an estimator of the mean of the population from which the sample was drawn.

To calculate the standard error of the mean:

106