Step-by-step explanation:
the number of pupils are in the lower school
= (1- 1/5 - ¼) × 600
= (20/20 - 4/20 - 5/20)×600
= (11/20) ×600
= 330 pupils
Answer:
c = <u>0.5 cm</u>
Step-by-step explanation:
Using the Sine rule in the triangle, then
= ( cross- multiply )
c × sin105° = 2 × sin15° ( divide both sides by sin105°
c = ≈ 0.5 cm ( to the nearest tenth )
Answer:
hope it's help you ok have a good day
Answer:
The minimum sample size needed is 125.
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:

For this problem, we have that:

99% confidence level
So
, z is the value of Z that has a pvalue of
, so
.
What minimum sample size would be necessary in order ensure a margin of error of 10 percentage points (or less) if they use the prior estimate that 25 percent of the pick-axes are in need of repair?
This minimum sample size is n.
n is found when 
So






Rounding up
The minimum sample size needed is 125.