Ms. Pacheco = P
Mr. Richards = R
Mr. Edwards = E
P = R + 3
E = 2R
R + E = 81
81 = R + 2R
81 = 3R
81 ÷ 3 = R
R = 27
P = R + 3
P = 27 + 3
P = 30
E = 2R
E = 2×27
E = 54
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
Answer:
$721.55
Step-by-step explanation:
658.95*1.095=721.55
Answer:
112 m^2
Step-by-step explanation:
A = b * h
b = 9 + 5 = 14 m
h = 8 m
So
A = 14 x 8 = 112 m^2
Answer:
18.72 cubic feet
Step-by-step explanation:
Volume of the aquarium = lwh
- l = 5.2 ft,
- w = 1.8 ft
- h = 2 ft
V = 5.2*1.8*2 = 18.72 cubic feet
