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>
12 sessions.
EXPLANATION:
each session is 1 3/4 hours.
We need enough sessions for 21 hours.
the equation is 1 3/4 x f = 21
using the multiplication property of equality, we can do 21 divided by 1 3/4
The answer is 12 sessions.
Hope it helps!
the formula for the circumference of a cirlce is πd. the diameter is 2r which in this case is 0.5. therefore the circumference is 0.5π, or 1.5708 (rounded)
17.55 divided by 5 is 3.51
So each section is 3.51 feet long
Answer: x=5 bc 5 times 5 is 25
Ste-by-step explanation: