Four levels, coded as −3, −1, 1, and 3 were chosen for each of two variables X1 and X2, to provide a total of sixteen experimental conditions when all possible combinations (X1,X2) were taken. It was decided to use the resulting sixteen observations to fit a regression equation including a constant term, all possible first-order, second-order, third-order and fourth-order terms in X1 and X2. The data were fed into a computer routine which ususlly obtains a vector estimate b = (X X) −1X Y The computer refused to obtain the estimates. Why? The experimenter, who had meanwhile examined the data, decided at this stage to ignore the levels of variable X2 and fit a fourth-order model in

step-by-step explan mxfcg'k; uafwgzfgjhklhgation:

+25 = x

step-by-step explanation:

here x is the hypotenuse of a right triangle whose legs are 7 and 24.   by the pythagorean theorem, 7² + 24² must equal x²:

x² = 49 + 576 = 625.   thus, x = +√625 = +25 = x

15%

step-by-step explanation:

use the table and count the number of guesses that has two correct answers.

the following are two correct answers

10010, 01100, 11000

a total of 3 numbers having 2 correct guesses out of 20 questions.

probability of getting 2 correct guesses = the number of questions getting 2 correct answers / total number of questions.

= 3/20

to convert it into percent multiply by 100, we get

= 3/20 * 100

= 15%

the answer is 15%

you.