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
Old coordinate
As center of dilation is origin the scale factor only multiplied with B
So
new coordinate
B'
- 1/2(2,-6)
- (2/2,-6/2)
- (1,-3)
Answer:
4/7/10
40/7 which is equal around 5. something...round
5 is your answer
Step-by-step explanation:
Hey there!
When they are asking which of them are equal we need to solve a, b, c and d and see if they match up to 6x^2-2x-20.
<u>Starting with A: </u>
Expand:
3 x 2x^2 + 3 x -x + 3 x -6
Simplify 3 x 2x^2 to 6x^2
6x^2 + 3 x -x + 3 x -6
Regroup.
6x^2 = 3x + 3 x -6
Simplify 3 x -6 to -18
6x^2 - 3x - 18
That does not match up to 6x^2-2x-20.
A is INCORRECT.
<u>Solving B:</u>
Collect like terms:
4x - 2x + 2x^2 - 20
The ones bolded are like terms.
So, we now collect them and add them.
4x^2 + 2x^2 = 6x^2
6x^2 - 2x - 20
That matches up with 6x^2-2x-20.
B is CORRECT.
<u>Solving C:</u>
Multiply the parentheses then multiply:
6x^2-12x+10x-20
Collect like terms:
6x^2 - 2x - 20
This matches up with 6x^2-2x-20.
Thus, C is CORRECT.
<u>Solving D:</u>
Multiply the terms in the parentheses by -2:
6x^2 - 2x - 2 x 10
Multiply the numbers:
6x^2 - 2x - 20
This also matches up with 6x^2 - 2x - 20 / they are <u>equal.</u>
Thus, D is also CORRECT.
<h3>Therefore, our answers are: </h3><h2><u>B, C, D </u></h2>
Thanks a ton for using Brainly! :)
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