Answer:
-7x +18
Step-by-step explanation:
ok this the work
4(2x-7) and 5(3x-2) distribute both
8x−28 15x−10
-15x +28 -15x +28 8x-15x is -7x -10+28 is 18
-7x+18
Answer:
For mean
To show the mean of height measures for 40 students, you need to write-out exactly 40 heights into a calculator and add them up.
Then divide that total number by 40.
Step-by-step explanation:
Eg for 4 students
5 , 5.1, 5.2, 5.7 = 21ft
21/4 = 5.25ft.
Apply the same method but use 40 measures in addition for calulator or long addition. Then divide by 40.
The improper fraction to that is 167/3
9 = - X + 8
move +8 to the other side
sign changes from +8 to -8
9-8= -x+8-8
9-8= -x
1= -x
mutiply both sides by -1 to get +x
(1)(-1) =(-x)(-1)
Answer: x=-1
For large sample confidence intervals about the mean you have:
xBar ± z * sx / sqrt(n)
where xBar is the sample mean z is the zscore for having α% of the data in the tails, i.e., P( |Z| > z) = α sx is the sample standard deviation n is the sample size
We need only to concern ourselves with the error term of the CI, In order to find the sample size needed for a confidence interval of a given size.
z * sx / sqrt(n) = width.
so the z-score for the confidence interval of .98 is the value of z such that 0.01 is in each tail of the distribution. z = 2.326348
The equation we need to solve is:
z * sx / sqrt(n) = width
n = (z * sx / width) ^ 2.
n = ( 2.326348 * 6 / 3 ) ^ 2
n = 21.64758
Since n must be integer valued we need to take the ceiling of this solution.
n = 22