Answer:
80
Step-by-step explanation:
area of trapezoid is given by formula
Area = 
h
where a is one base, b is another base and h is height
In given case, we have
a= 7+7+3 = 17
b= 3
h= 8
Substituting the values
Area= 
x 8
= 
x 8
= 10 x 8
= 80
!
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
For sample size
calcualtions we need the following. The width of the interval, from one end
point to the center is:
z * sx / sqrt(n) =
w and solving for n gives:
<span> n = (z * sx / w) ^ 2 </span>
remember that n needs to
be an integer. Always take the ceiling, i.e., round up. If you round down then
the width of the interval will not be correct, it will be too wide. By rounding
up, the interval will be more narrow than asked for, but this is a good thing.
It means there is more precision in the estimate.
<span> here we have </span>
z = 2.05
w = 0.04 * 152 = 6.08
n = (z * sx / w) ^ 2 n =
(2.05 * 26 / 6.08)^2
n = 76.8506
Round of the answer since
n must be an integer.
<span>n = 77 </span>
Answer:
I think the answer is 10 hours
the 11.95 seems wrong
Step-by-step explanation:
multiply by 22.5 y
3.75 y + 22.5 = 6y
y = 10
Answer:
Cost to construct the road = 775000 rupees
Step-by-step explanation:
Square field has a side = 150 m
Area of the field = (Side)²
= (150)²
= 22500 m²
Length of the park with road around the field = 150 + 2×(width of the road)
= 150 + (2×5)
= 160 m
Similarly, width of the park with road around the field = 160 m
Area of the park with road = (Side)²
= (160)²
= 25600 m²
Area of road = Area of the park with road - Area of the park
= 25600 - 22500
= 3100 m²
Since, cost of constructing the road = 250 rupees per square meter
Cost to construct the road with the given area = 250 × 3100
= 775000 rupees
