A student keeps track of how long it takes her to write her signature.

Question

A student keeps track of how long it takes her to write her signature. She collects the data in one sitting so that she can see if there is a change in her writing rate over time. She wants to know if it takes her a longer time due to fatigue or a shorter time due to repetition. Her data are given in the table.

Number of Time

Signatures (seconds)

1 4.42

2 8.66

3 13.51

4 16.26

5 23.6

6 28.11

7 30.17

8 32.56

9 33.68

10 35.87

When using Excel to find the equation of the trendline, she has an option for the type of model. She chooses a linear model but notices that it does not seem to model the pattern closely. Next, she chooses polynomial models of different degrees to see how closely they fit the points. Each graph and its equation follow. Use each equation to predict how long it will take to write 7 signatures. Then find the residual for each prediction.

Answer 1

Each graph and its equation follow. ???