Answer:
≈ 82 feet
Step-by-step explanation:
Since the triangle is right use Pythagoras' identity to calculate distance (d)
The square on the hypotenuse is equal to the sum of the squares on the other 2 sides.
Here the hypotenuse is the distance (d) between the 2 poles, hence
d² = 80² + 45² = 6400 + 2025 = 8425 ( take the square root of both sides )
d = ≈ 82 feet ( to the nearest foot )
Answer:
b. It will decrease by a factor of 2
Step-by-step explanation:
In a sample with a number n of people surveyed with a probability of a success of , and a confidence interval
, we have the following confidence interval of proportions.
In which
z is the zscore that has a pvalue of .
The lower end of the interval is given by:
The upper end of the interval is given by:
The length of the interval is the subtraction of the upper end by the lower end, so it is:
This means that the length is inverse proportional to the square root of the size of the sample.
So, if the sample size is multiplied by 4, the length of the interval is going to decrease by a factor of 2.