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:
They're already matched... at least they way you typed it.
Step-by-step explanation:
A ratio is a comparison of two numbers as a fraction or quotient. A part-whole ratio is a ratio comparing a part of something to the whole thing. A part-part ratio is ratio comparing two different parts of one whole.
Answer:
37.5 miles
Step-by-step explanation:
Distance covered in 4 hours = 150 miles
Distance covered in 1 hour = 150/4 = 37.5 miles
Answer:
62.8
Step-by-step explanation:
10*2=20
20*3.14= 62.8
HOPE IT HELPS
X represent the number of laps Marcy swam, 114x represent the number of times Toni swam.
20 + 0.80(114x) + 15 + 0.85x = 257
20 + 91.2x + 15 + 0.85x = 257
92.05x + 35 = 257
Required equation is 92.05x + 35 = 257
