Step-by-step explanation:
log x = 1 + a
a = log x - 1
log y = 1 - a
a = 1 - log y
So
log x - 1 = 1 - log y
log x + log y = 2
log (xy) = 2
xy = 100
Answer:
x = ±sqrt(2)
Step-by-step explanation:
8x^2 - 5 = 11
Add 5 to each side
8x^2 - 5+5 = 11+5
8x^2 = 16
Divide each side by 8
8x^2 = 16/8
x^2 = 2
Take the square root of each side
sqrt(x^2) = ±sqrt(2)
x = ±sqrt(2)
Answer:
Q1
slope=0.16
intercept=30.2
Q2
78.2
Q3
36%
Step-by-step explanation:
Question 1
We are given that
xbar=280
sx=30
ybar=75
sy=8
r=0.6
The regression line can be written as
y=a+bx
a=intercept
b=slope
where

and

b=0.6*(8/30)
b=0.16
a=75-0.16*280
a=30.2
Thus,
slope=0.16
intercept=30.2
Question 2
The regression line in the given scenario
y=30.2+0.16x
Julie pre exam total before the exam was 300.
y=30.2+0.16*300
y=30.2+48=78.2
So, the predicted final exam score of Julie is 78.2.
Question 3
R² denotes the variation in dependent variable y explained by the linear relationship of x and y.
R²=0.6²=0.36
Thus, the proportion of the variation in final exam scores that is explained by the linear relationship between pre-exam scores and final exam scores is 36%.
So, by using above rule for finding average; here number of the numbers is 2 and sum of these two numbers is 25+50=75. Hence, average of 25 and 50 is: 75/2=37.5. Thus, average of 25 and 50 is 37.5.