As part of a study at a large university, data were collected on n= 224 freshmen computer science (CS) majors in a particular year. The researchers were interested in modeling y, a student's grade point average (GPA) after three semesters, as a function of the following independent variables (recorded at the time the students enrolled in the university): X1 = average high school grade in mathematics (HSM) × 2 = average high school grade in science (HSS) X 3 = average high school grade in English (HSE) XA = SAT mathematics score (SATM) X5 = SAT verbal score (SATV) A first-order model was fit to the data with the following results: SOURCE DF MS F VALUE PROB>F S MODEL 28.64 5.73 11.69 .0001 ERROR 218 106.82 0.49 TOTAL 223 135.46 ROOT MSE DEP MEAN 0.700 4.635 R-SQUARE ADJ R-SQ 0.211 0.193 I FOR O ERROR PARAMETER =0 PROB>ITI PARAMETER STANDARD VARIABLE ESTIMATE INTERCEPT 0.0001 0.0003 0.3432 2.327 0.039 5.817 X1 (HSM) X2 (HSS) X3 (HSE) 0.146 0.037 3.718 0.036 0.038 0.950 0. 1637 0. 1702 0.4915 Test to determine if the model is adequate for predicting GPA. Use a = .01. 0.055 0.00094 -0.00041 0.040 1.397 X4 (SATM) X5 (SATV) 0.00068 0.0059 1.376 -0.689

Studies have shown that people who suffer sudden cardiac arrest have a better chance of survival if a defibrillator shock is administered very soon after cardiac arrest. How is survival rate related to the time between when cardiac arrest occurs and when the defibrillator shock is delivered? The accompanying data give y = survival rate (percent) and x = mean call-to-shock time (minutes) for a cardiac rehabilitation center (in which cardiac arrests occurred while victims were hospitalized and so the call-to-shock time tended to be short) and for four communities of different sizes. Mean call-to-shock time, x 2 6 79 12 Survival rate, y (a) Construct a scatterplot for these data. y 12. 10 O 8 6 20 40 60 91 44 32 6 4 80 100 y 100 80 60 ELL 40 20 2 4 6 8 X 12 10 8 6 4 20 40 60 (b) Find the equation of the least-squares line. (Round your values to four decimal places.) ŷ= Jx 80 100 10 12 (c) Use the least-squares line to predict survival rate for a community with a mean call-to-shock time of…

Suppose an oceanographer monitors the daily salinity of a particular ocean in relation to the temperature of the water. The oceanographer plots the data with temperature, in degrees Celsius (°C), along the horizontal axis and salinity, in parts per thousand (ppt), along the vertical axis.   Select the true statement about the data point identified by the arrow. An ocean temperature of 21 °C causes the salinity to be 29 ppt. The predicted salinity is 29 ppt when the ocean temperature for the day is 21 °C. An ocean temperature of 29 °C corresponds to a salinity level of 21 ppt. The observed salinity is 29 ppt when the ocean temperature for the day is 21 °C. There is no relationship between the temperature of the ocean on a given day and salinity.

The correlation coefficient between the yearly returns of two mutual funds is 0.20. What does that mean about the strength and direction of the linear relationship between the returns of the two funds?