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
U write it as 1/6+1/6+1/6+1/6=4/6
Answer:
Step-by-step explanation:
First, find the magnitude of the vector:
Then, divide each component of the vector by the magnitude to get the unit vector and rationalise:
Let's solve the equation step-by-step
Step 1) Simplify both sides of the equation
3+ j/11 = 2
1/11j+3=2
Step 2) Subtract 3 from both sides
1/11j + 3 - 3 = 2 - 3
1/11j = -1
Step 3) Multiply both sides by 11
11 x (1/11j) = (11) x (-1)
j = -11
Answer is.. J = -11
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