I suppose that the expression you wanted to write is

. If so, then we have:
Answer:
A sample of 499 is needed.
Step-by-step explanation:
In a sample with a number n of people surveyed with a probability of a success of
, and a confidence level of
, we have the following confidence interval of proportions.

In which
z is the zscore that has a pvalue of
.
The margin of error is given by:

In this question, we have that:

90% confidence level
So
, z is the value of Z that has a pvalue of
, so
.
How large a sample would be required in order to estimate the fraction of tenth graders reading at or below the eighth grade level at the 90% confidence level with an error of at most 0.03
We need a sample of n, which is found when
. So






Rounding up
A sample of 499 is needed.
Answer:
42.1
Step-by-step explanation:
The height of the main triangle is,
h = 47√3/2 (since it's an 30-60-90 triangle)
so to find x,
tan(44) = h/x
x = h/tan(44)
x = 42.1 (rounded to the nearest tenth)
Answered by GAUTHMATH
Let sister be s. Matthew, M
Matthew is 7years older than twice the age of his sister
M = 7 + 2s
13 = 7 + 2s. 7 crosses the equality to other side and becomes -7
13 - 7 = 2s
6 = 2s Divide both sides by 2
6/2 = 2s/2
3 = s
Sister is 3 years old.
Answer:
4,500,000 population in 1950
Step-by-step explanation:
the equation is 4p + 1,000,000 = 19,800,000