B because in commutative property of addition the numbers switch but they do not change the sign nor the numbers. hope this helped
Answer:a. μ = 9.667 hours
b. σ = 1.972 hours
c. SE = 0.805 hour
Sample size (n) = 6
Sample data (xi) = 10, 8, 9, 7, 11, 13
a. Mean time spent in a week for this course by students:
Sample mean is given by:
Mean time spent in a week per student is 9.667 hours
b. Standard deviation of the time spent in a week for this course by students:
Standard deviation is given by:
c. Standard error of the estimated mean time spent in a week for this course by students:
Standard error is given by:
X of 20% = y
x - y = 75
x = total amount
y = discounted amount
x * 20/100 = y
x * 0.2 = y
replace y with 0.2x in other equation
x - y = 75
1x - 0.2x = 75
0.80x = 75
x = 75/.8
x = 93.75
Check:
93.75 * 20/100 = 18.75
93.75 - 18.75 = 75
x = 93.75
y = 18.75
Answer: Total amount without discount is $93.75
//BTW not sure about this, but kind of make sense
The answer I got is (2x^2+x-15)
