Answer:
He must survey 123 adults.
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 z-score that has a p-value of
.
The margin of error is:

Assume that a recent survey suggests that about 87% of adults have heard of the brand.
This means that 
90% confidence level
So
, z is the value of Z that has a p-value of
, so
.
How many adults must he survey in order to be 90% confident that his estimate is within five percentage points of the true population percentage?
This is n for which M = 0.05. So






Rounding up:
He must survey 123 adults.
Answer:
2/21x7/5 is 14/105
Step-by-step explanation:
You add up all of the sides
Answer:
a = 30/5 = 6
Step-by-step explanation:
Answer:
c. 61.25 kg
Step-by-step explanation:
The margin of error in estimating the true mean weight of male baluga whales in the Artic Ocean.
a. 15.31 kg
b. 51.40 kg
c. 61.25 kg
d. 80.49 kg
Margin of Error Formula= z × Standard deviation/√n
95% confidence interval = 1.96
Standard deviation = 125kg
n = 16 samples
Margin of error= 1.96 × 125/√16
= 1.96 × 125/4
= 245/4
= 61.25kg
The margin of error in estimating the true mean weight of male baluga whales in the Artic Ocean is 61.25kg