Answer:
2,655 students
Step-by-step explanation:
The z-score for a 99% confidence interval is z = 2.576
The standard error for a proportion p is:
For a proportion of p =0.20, in order to ensure a standard error of 0.02, the sample size 'n' must be:
Rounding up to the next whole student, the sample size needed is 2,655 students.
Answer:
<em>24 minutes</em>
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Step-by-step explanation:
Given:
Distance per lap = 2 miles
Speed of Lou Lambert = 160 miles/hr
Speed of Ralph Redding = 170 miles/hr
Speed difference between the two = 170 - 160 = 10 miles/hr
Therefore, we can say that <em>Ralph gains 10 miles in 60 minutes </em>over Lou<em>.</em>
We have to find the time in which Ralph will gain 2 laps i.e. 2 2 = 4 miles.
Let us use unitary method to find the required time.
10 miles are gained by Ralph in 60 minutes
1 mile will be gained in
4 miles will be gained in 6 4 = <em>24 minutes</em>