Problem 9-1

The linear regression of the low-flow series of streams X and Y (Eq. 7-24) leads to: Y= α + β X, in which α = 23.67, and β = 0.66.  ANSWER. The correlation coefficient is: r= 0.781.  ANSWER. The standard error of estimate is: s_e= 14.10.  ANSWER.

Problem 9-2

THANK YOU FOR RUNNING EH700B.
THIS PROGRAM SOLVES THE TWO-PREDICTOR-VARIABLE NONLINEAR REGRESSION FIT.
ENTER NUMBER OF DATA SETS: 12
DO YOU WANT TO INPUT THE DATA INTERACTIVELY (Y(J),X1(J),X2(J)) (Y/N)?: n
READING 12 DATA SETS FROM YOUR INPUT FILE.
DO YOU WANT YOUR OUTPUT TO THE SCREEN (Y/N)?: y

TWO-PREDICTOR-VARIABLE NONLINEAR REGRESSION FIT:
Y = A * (X1**B1) * (X2**B2)

COEFFICIENT A= 0.029
EXPONENT B1= 1.128
EXPONENT B2= 0.260

STANDARD ERROR SE: 11.481

THANK YOU FOR RUNNING EH700B. PLEASE CALL AGAIN.

ANSWER.

Problem 9-3

The regression equation is: i = a/(t_r + b), in which i = rainfall intensity, t_r = rainfall duration, and a = 577.71 and b = 53.52.    ANSWER. The correlation coefficient is: r = 0.97 ANSWER.