Answer:
-20
Step-by-step explanation:
Replace X by 3
f(3) = -2(3)^2+ (3)-5 = -20
Answer:
It would be 8 PM.
Step-by-step explanation:
If you keep decreasing 23 by 7 till you get to -5, it would have to be decreased 4 times to get to -5. This means that the time would have to go up 4 times the 45 minute rate, which would be 3 hours. 5 pm + 3 hours is 8 PM.
Answer:
We have strong evidence that on average, students study less than 150 minutes per night during the school week
Step-by-step explanation:
Normal distribution:
mean μ₀ = 150
Sample:
Sample size n = 272
Sample mean x = 141
Sample standard deviation s = 66
The standard error of the sample mean SE = σ /√n
SE = 66/√272
SE = 66 / 16,49
SE = 4
Test Hypothesis:
Null hypothesis H₀ x = μ₀
Alternative hypothesis Hₐ x < μ₀
z(s) test statistics is:
z(s) = ( x - μ₀ ) / s/√n
z(s) = - 9 /4
z(s) = - 2,25
p-value for that z(s) p-value = 0,0122
Then for α = 0,05 p-value < 0,05
We are in the rejection region we need to reject H₀
