A study was conducted that showed strong positive correlation between eating strawberries and the number of freckles on a person
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Answer:
We need at least 243 stores.
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 of the interval is:
For this problem, we have that:
95% confidence level
So , z is the value of Z that has a pvalue of
, so
.
Determine the number of stores that must be sampled in order to estimate the true proportion to within 0.04 with 95% confidence using the large-sample method.
We need at least n stores.
n is found when M = 0.04. So
Rounding up
We need at least 243 stores.
Answer
given,
on first stop
number of car = 20 and number of trucks = 18
on second stop
number of car = 18 and number of trucks = 10
we need to calculate which rest stop has higher ratio of car to truck.
Rest Stop 1
ratio= r₁ =
r₁ =
r₁ =
Rest Stop 2
ratio= r₂ =
r₂ =
r₂=
hence, r₂ > r₁
rest stop 2 has more car to truck ratio than rest stop 1