Question 1
Suppose we wanted to predict the selling price of a house using its size in a certain area of a city. A random sample of six houses were selected from the area. The data is presented in the following table with size given in hundreds of square feet, and sale price in thousands of dollars.
Size (Xi) |
12 |
15 |
18 |
21 |
24 |
27 |
Price (Yi) |
60 |
85 |
75 |
105 |
120 |
110 |
a) Find the least squares estimate for the regression line Yi= b0+ b1Xi+ ei.
b) What would be your estimate of the sale price for a 2,000 square foot house?
c) Estimate the standard deviation of the error term ei
d) Compute the correlation coefficient.
e) What proportion of the variability in the sale price can be explained using this model (i.e. what is R2)?
f) Test the null hypothesis that b1= 0 (perform a two-sided test), using α = 0.05. Is the model useful?
g) Perform the regression using SAS, and give the p-value to the test in part f ). Verify that the p-value agrees with your conclusion in part f ).
Question 1 Suppose we wanted to predict the selling price of a house using its size...
Question 1 (The following data is from Q1 of HW2) Suppose we wanted to predict the selling price of a house using its size in a certain area of a city. A random sample of six houses were selected from the area. The data is presented in the following table with size given in hundreds of square feet, and sale price in thousands of dollars: Size (X121518 21 24 27 Price (Y)6085 75 105 120 110 We are interested in...
In a study, the protein absorption (Y) for seven concentration levels (X) of that protein were measured: Be Specific with answers Conc. Level (Xi) 4 6 8 10 12 14 16 Absorption (Yi) 10 15 18 18 24 22 26 a) Find the least squares estimate for the regression line Yi = b0 + b1Xi+ ei. b) What would be your estimate of the absorption when the concentration level is 10? c) Estimate the standard deviation of the error term...
House Selling Price Data for 100 homes relating y = selling price (in dollars) to x = size of the house (in square feet) results in the regression line that is shown below. y= 9161 + 77.008x the slope estimate has standard error 6.262 Show all steps of a two-sided significance test of independence. Could the sample association between these two variables by explained by random variation? a) Assumptions b) Hypotheses: c) Test Statistics: d) p-value: e) Conclusion:
A real estate builder wishes to determine how house size is influenced by family income, family size, and education of the head of household. House size is measured in hundreds of square feet, income is measured in thousands of dollars, and education is measured in years. A partial computer output is shown below. SUMMARY OUTPUT Regression Statistics Multiple R 0.865 R Square 0.748 Adjusted R Square _____ Standard Error 5.195 Observations 50 ANOVA df SS MS F Significance F Regression...
A real estate builder wishes to determine how house size (House) is influenced by family income (Income), family size (Size), and education of the head of household (School). House size is measured in hundreds of square feet, income is measured in thousands of dollars, and education is measured in years. The builder randomly selected 50 families and ran a multiple regression. The regression statistics are below: Regression Statistics R Square 0.748 Adjusted R Square 0.726 Standard Error 5.195 Observations 50...
[a] We want to predict the price of houses from the size of the house (sarft). Please graph a scatterplot and see if the association is linear enough. (20 pts) There is a fairly linear association with very few outliers. Statkey Descriptive Statistics for Two Quantitative Variables Summary Statistics sih 013695 293546014 77.192 102713 445 650000 Sample Siee 0.788 140.211 11204 145 600000 550000 Scatterplot Controls a Show Regression Line 450000 300000 50000 1500 [b] Find the regression equation for...
A local realtor wishes to study the relationship between selling price (in $) and house size (in square feet). A sample of 10 homes is selected at random. The data is given below: PRICE HOUSESIZE 100000 1600 107000 1750 121000 1900 124000 2150 132000 2400 140000 2300 144000 2400 158000 2700 170000 3000 182000 2900 a) Find the regression equation relating Price to Square Footage. b) Calculate the correlation coefficient, accurate to three decimal places c) Test the significance of...
1. Selling price in millions of shilling and size of homes Table Price Size Price Size Price Size (‘000) (sq. ft.) (‘000) (sq. ft.) (‘000) (sq. ft.) 268 1897 142 1329 83 1378 131 1157 107 1040 125 1668 112 1024 110 951 60 1248 112 935 187 1628 85 1229 122 1236 94 816 117 1308 128 1248 99 1060 57 892 158 1620 78 800 110 1981 135 1124 56 492 127 1098 146 1248 70 792 119 ...
1. One Price Realty Company wants to develop a model to estimate the value of houses in its inventory The office manager has decided to develop a multiple regression model to help explain the variation in house values. (25 points) The office manager has chosen the following variables to develop the model: X1 square feet X2- age in years x3- dummy variable for house style (1 if ranch, 0 if not) X4-2d dummy variable for house style (I if split...
Question 2 A research firm collected data on a sample of n= 30 drivers to investigate the relationship between the age of a driver and the distance the driver can see. The data is given below: Age Distance Age Distance 18 510 55 420 20 590 63 350 22 560 65 420 23 510 66 300 23 460 67 410 25 490 68 300 27 560 70 390 28 510 71 320 29 460 72 370 32 410 73 280...