The American Association of Individual Investors (AAII) On-Line Discount Broker Survey polls members on their experiences with discount brokers. As part of the survey, members were asked to rate the quality of the speed of execution with their broker as well as provide an overall satisfaction rating for electronic trades. Possible response (scores) ranged from 0 (unsatisfied) to 4 (very satisfied). For each broker summary scores were computed by calculating a weighted average of the scores provided by each respondent. Download the Excel FileBrokerRatings.xlsxfor aportion of the survey results (AAII website, February, 7. 2012).

Using the data in the file: BrokerRatings.xlsx

Brokerage	Speed	Satisfaction
Scottrade, Inc.	3.4	3.5
Charles Schwab	3.3	3.4
Fidelity Brokerage Services	3.4	3.9
TD Ameritrade	3.6	3.7
E*Trade Financial	3.2	2.9
Vanguard Brokerage Services	3.8	2.8
USAA Brokerage Services	3.8	3.6
Thinkorswim	2.8	2.6
Wells Fargo Investments	2.7	2.3
Interactive Brokers	4.0	4.0
Zecco.com	2.5	2.5

(a) Develop a scatter diagram for these data with the speed of execution as the independent variable.

(b) What does the scatter diagram development in part (a) indicate about the relationship between the two variables?

(c) Using the "Regression" command in excel, develop the least squares estimated regression equation. Note: the speed of execution is still theindependentvariable

(d) Provide an interpretation of the slope of the estimated regression equation.