Answer:
The 95% confidence interval based on this sample is =
[6.41, 7.79]
Step-by-step explanation:
The formula for Confidence Interval =
Mean ± z × standard deviation/√n
Sample mean = 7.1 hours
Standard deviation = 5 hours
n = 200 students
z = 95% confidence interval z score
= 1.96
C.I = 7.1 ± 1.96 × 5/√200
C.I = 7.1 ± 0.693
Hence, Confidence Interval
= 7.1 - 0.693
= 6.407
Approximately = 6.41
= 7.1 + 0.693
= 7.793
Approximately = 7.79
Therefore, the 95% confidence interval based on this sample is
[6.41, 7.79]
Answer:
x = -1 and x = 4
Step-by-step explanation:
Firstly solve the quadratic expression of
2x^2-6x-8 = 0....it gives you the two brackets of.....(2x-8)(x+1)=0
then...you equate the two brackets to 0.separately
2x-8 = 0....which gives you...x = 4...as the first solution..then..;
x+1 = 0....which gives you...x = -1...as the second solution
$1.25 because if you bought 2 packs of them it would be $2.50 so you would be 0.09 cheaper
Answer is D the last one
if the equation is y= 3 lx + 2l
if you solve for x then the zero is x= -2
if y intercept .. so x = 0
then point is (0,6)
hope that helps
