Author: Anonymous

Bats can catch small insects in complete darkness by emitting __________ sound waves.  This ability is called _______________.

The ability to sense the movement of different body parts (for example to know that I moved my hand towards my face) is called:

Data collected for an auto repair shop includes the type of repair. Repairs were listed as mechanical, electrical, maintenance, and tire replacement. You are trying to determine if the cost of the repair depends on the type. How would you include this categorical data in a regression model? Be specific and indicate what the columns would look like in Excel. How many columns would you need?

Multiple regression analysis was used to study how an individual’s income (y in thousands of dollars) is influenced by age (x1 in years), level of education (x2 ranging from 1 to 5), and the individual’s gender (x3 where 0 = female and 1 = male). The following is a partial result of a computer program that was used on a sample of 20 individuals. ANOVA       df SS Regression 3 84 Residual 16 112 Compute the coefficient of determination for this analysis. (Round to 4 decimal places)

Assume you have noted the following prices for books and the number of pages that each book contains. Book Pages Price A 500 $7.00 B 700 7.50 C 750 9.00 D 590 6.50 E 560 7.50 F 650 7.00 G 475 5.00   Regression Statistics Multiple R 0.79194025 R Square 0.62716936 Adjusted R Square 0.55260323 Standard Error 0.80609586 Observations 7 ANOVA   df SS MS F Significance F Regression 1 5.465333 5.465333 8.41091496 0.033784497 Residual 5 3.24895271 0.64979054 Total 6 8.71428571         Coefficients Standard Error t Stat P-value Lower 95% Upper 95% Lower 95.0% Upper 95.0% Intercept 1.41532767 1.97392859 0.71701057 0.50545648 -3.658817306 6.48947265 -3.6588173 6.48947265 Pages 0.00937105 0.00323122 2.90015775 0.0337845 0.001064933 0.01767718 0.00106493 0.01767718 Is this regression equation statistically significant? How do you know? Be specific and use numbers from the output above.  

Output from a data set is listed below. Using the data below determine if there are any outliers. If yes, which observation and how do you know? What values are you using to determine outliers? RESIDUAL OUTPUT Observation Predicted Price Residuals Standard Residuals 1 6.10085504 0.89914496 2.22189431 2 7.97506599 -0.475066 -0.6455916 3 8.44361873 0.55638127 0.75609511 4 6.94424997 -0.44425 -0.6037141 5 6.66311833 0.83688167 1.13728153 6 7.50651326 -0.5065133 -0.6883269 7 5.86657868 -0.8665787 -1.1776383

An economist working for a large retail chain estimates the following multiple regression model for daily cold beverage sales: Q=500-20P+ 5T  Q is the predicted quantity of units sold per day, P is the price per unit (in dollars), and T is the daily high temperature (in degrees Fahrenheit). The model has an R-squared value of 0.81. What does this R-squared value mean in this context?

In regression analysis with more than one independent variable, when is the t test statistic used and what does its p-value mean? 

The following estimated regression equation has been proposed to predict sales at a fast food outlet.   y = 18 – 2×1 + 7×2 + 15×3 ​where x1 = the number of competitors within 1 mile x2 = the population within 1 mile (in 1000s) x3 = 1 if drive-up windows are present; 0 otherwise  = estimated sales (in $1000s) What is the interpretation of 15 (the coefficient of x3) in the regression equation? Be specific within the context of the problem.

A researcher found a standardized residual for a specific observation equaled -2.87. The researcher was deciding whether to keep the observation in the model. He wanted to know if it was influential and calculated the leverage with the following data: The data set had 10 observations and the mean of x was 69.5. The x value for the observation in question was 76.2. The sum of the squared differences from x-bar equals 4722.5. What is the leverage value for this observation? (round to 4 decimal places)