Question

Research into the relationship between hours of study and grades show widely different conclusions. A recent...

Research into the relationship between hours of study and grades show widely different conclusions. A recent survey of graduates who wrote the Graduate Management Admissions Test (GMAT) had the following results.

Hours Studied Average Score

(Midpoint)

64 350

72 450

79 550

106 650

99 750

The Excel output for this regression is as following

SUMMART OUTPUT

____________________________

   Regression Statistics

____________________________

Multiple R 0.919958

R Square 0.846322

Adjusted R Square 0.795097

Standard Error 71.57225

Observations 5

Anova

___________________________________________________________________________________________

   DF SS MS F Sign. F

___________________________________________________________________________________________

   84632.2 84632.2 16.521 0.0268

Regression. 1 4 4 4 6

   15367.7 5112.58

Residual 3 6 7

Total 4 100000

___________________________________________________________________________________________

   Coefficient Standard Lower Upper

   s Error t Stat P-Value 95% 95%

___________________________________________________________________________________________

   171.192 0.4921 411.24

Intercept -133.568 8 -0.78022 6 -678.38% 4

   0.0268

X Variable 1 8.137715 2.00207 xxxxxx 6 1.7662 14.509

___________________________________________________________________________________________

a) How accurate is this regression at predicting GMAT scores base on hours studied? Explain.

b) What is the regression equation for this relationship?

c) Use the regression equation to predict the average score for each category of hours studies.

d) Calculate the t statistic to determine approximately how “significant” this regression is (note that the t may be greater than or less than the value from the t table).

Homework Answers

Answer #1

Q1: From ANOVA table p- value = 0.0268

Since p-value is less than 0.05,we reject the null hypothesis and can say that the regression model is significant to predict the GMAT scores.

Coefficient of determination, r2 = 0.8463

So about 84.63% variation in the response variable GMAT score explained by predictor variable hours studied.

--

Q2: Regression equation :

ŷ = -133.5681 + (8.1377) x

--

Q3:

X Y Predicted score, ŷ
64 350 -133.5681 + (8.1377) * 64 = 387.2457
72 450 -133.5681 + (8.1377) * 72 = 452.3474
79 550 -133.5681 + (8.1377) * 79 = 509.3114
106 650 -133.5681 + (8.1377) * 106 = 729.0297
99 750 -133.5681 + (8.1377) * 99 = 672.0657

--

Q4: Test statistic:

t = b /se(b1) = 8.137715/ 2.00207 = 4.0647

Know the answer?
Your Answer:

Post as a guest

Your Name:

What's your source?

Earn Coins

Coins can be redeemed for fabulous gifts.

Not the answer you're looking for?
Ask your own homework help question
Similar Questions
The following data was collected to explore how the average number of hours a student studies...
The following data was collected to explore how the average number of hours a student studies per night and the student's GPA affect their ACT score. The dependent variable is the ACT score, the first independent variable (x1) is the number of hours spent studying, and the second independent variable (x2) is the student's GPA. ACT Score Study Data Study Hours GPA ACT Score 1 2 19.91 1 2 19.69 2 2 25.52 2 3 29.67 2 4 29.77 A...
Thane Company is interested in establishing the relationship between electricity costs and machine hours. Data have...
Thane Company is interested in establishing the relationship between electricity costs and machine hours. Data have been collected and a regression analysis prepared using Excel. The monthly data and the regression output follow:    Month Machine Hours Electricity Costs January 3,500 $ 18,900 February 3,900 $ 22,000 March 2,900 $ 14,000 April 4,100 $ 24,000 May 4,800 $ 28,750 June 4,300 $ 23,000 July 5,500 $ 25,250 August 4,500 $ 23,250 September 3,000 $ 16,500 October 4,700 $ 27,000 November...
A business is evaluating their advertising budget, and wishes to determine the relationship between advertising dollars...
A business is evaluating their advertising budget, and wishes to determine the relationship between advertising dollars spent and changes in revenue. Below is the output from their regression. SUMMARY OUTPUT Regression Statistics Multiple R 0.95 R Square 0.90 Adjusted R Square 0.82 Standard Error 0.82 Observations 8 ANOVA df SS MS F Significance F Regression 3 23.188 7.729 11.505 0.020 Residual 4 2.687 0.672 Total 7 25.875 Coefficients Std Error t Stat P-value Lower 95% Upper 95% Intercept 83.91 2.03...
In models B through D, what seems to be the relationship between the burglary rate and...
In models B through D, what seems to be the relationship between the burglary rate and the percent of the 18-64 population who are young adults (18-24)? Select one: a. It is difficult to describe the relationship; the young adult variables were all significant at 5% in models B, C, and D, but the signs and sizes of the coefficients were very different between models. b. Conclusions about the relationship between young adults and the burglary rate are difficult to...
10. In Exercise 6, we examined the relationship between years of education and hours of television...
10. In Exercise 6, we examined the relationship between years of education and hours of television watched per day. We saw that as education increases, hours of television viewing decreases. The number of children a family has could also affect how much television is viewed per day. Having children may lead to more shared and supervised viewing and thus increases the number of viewing hours. The following SPSS output displays the relationship between television viewing (measured in hours per day)...
The following data is used to study the relationship between miles traveled and ticket price for...
The following data is used to study the relationship between miles traveled and ticket price for a commercial airline: Distance in miles:        300      400      450      500      550      600      800      1000 Price charged in $:      140      220      230      250      255      288      350      480 SUMMARY OUTPUT Regression Statistics Multiple R                   0.987 R Square 0.975 Adjusted R Square 0.971 Standard Error 17.352 Observations 8 ANOVA df SS MS F Significance F Regression 1 70291.3 70291.3 233.4 4.96363E-06 Residual 6 1806.6 301.1 Total...
1. Jensen Tire & Auto is in the process of deciding whether to purchase a maintenance...
1. Jensen Tire & Auto is in the process of deciding whether to purchase a maintenance contract for its new computer wheel alignment and balancing machine. Managers feel that maintenance expense should be related to usage, and they collected the information on weekly usage (hours) and annual maintenance expense (in thousands of dollars). SUMMARY OUTPUT Regression Statistics Multiple R 0.9272 R Square 0.8597 Adjusted R Square 0.8422 Standard Error 4.1466 Observations 10 ANOVA df SS MS F Significance F Regression...
True or false: at the 5% level of confidence the intercept is significantly different from zero?...
True or false: at the 5% level of confidence the intercept is significantly different from zero? SUMMARY OUTPUT Regression Statistics Multiple R 0.98711 R Square 0.974387 Adjusted R Square 0.965849 Standard Error 47.4523 Observations 9 ANOVA df SS MS F Significance F Regression 2 513960.7 256980.4 114.1262 1.68E-05 Residual 6 13510.32 2251.72 Total 8 527471.1 Coefficients Standard Error t Stat P-value Lower 95% Upper 95% Lower 95.0% Upper 95.0% Intercept -100.805 48.43281 -2.08133 0.082583 -219.316 17.70612 -219.316 17.70612 Well Depth...
] A partial computer output from a regression analysis using Excel’s Regression tool follows. Regression Statistics...
] A partial computer output from a regression analysis using Excel’s Regression tool follows. Regression Statistics Multiple R (1) R Square 0.923 Adjusted R Square (2) Standard Error 3.35 Observations ANOVA df SS MS F Significance F Regression (3) 1612 (7) (9) Residual 12 (5) (8) Total (4) (6) Coefficients Standard Error t Stat P-value Intercept 8.103 2.667 x1 7.602 2.105 (10) x2 3.111 0.613 (11)
Dep.= Mileage Indep.= Cylinders SUMMARY OUTPUT Regression Statistics Multiple R R Square Adjusted R Square Standard...
Dep.= Mileage Indep.= Cylinders SUMMARY OUTPUT Regression Statistics Multiple R R Square Adjusted R Square Standard Error Observations 7.0000 ANOVA Significance df SS MS F F Regression 12.4926 Residual Total 169.4286 Standard Coefficients Error t Stat P-value Lower 95% Upper 95% Intercept 38.7857 Cylinders -2.7500 SE CI CI PI PI Predicted Predicted Lower Upper Lower Upper x0 Value Value 95% 95% 95% 95% 4.0000 1.9507 6.0000 1.1763 Is there a relationship between a car's gas MILEAGE (in miles/gallon) and its...