TO solve this question on "how large of a sample must Beth have to get a margin of error less than 0.04", we will use the margin of error formula:
Here, for a 80% confidence level,
(given)
Thus, margin of error, E=0.04
rearranging we get:
Plugging in gives us:
Thus, Beth's sample for the true proportion of high school students in the area who attend their home basketball games must have 256 students.
Answer:
First option is the correct choice.
Step-by-step explanation:
Best Regards!
Answer: 7.5
Step-by-step explanation:
First, converting R percent to r a decimal
r = R/100 = 7.5%/100 = 0.075 per year,
then, solving our equation
I = 1200 × 0.075 × 2 = 180
I = $ 180.00
Answer: The following three equations could be used to determine the rate:
x*(time there) = 3 miles
(x+1)*(time back) = 3 miles
(time there) + (time back) = 2.5 hr
Step by step (including the actual solution x):
Equation for the trip there:
x*(time there) = 3 miles
Equation for the trip back:
(x+1)*(time back) = 3 miles
And we also know that:
(time there) + (time back) = 2.5 hr
So we have three equations with three unknowns and can solve for x. Let us call
(time there): t1
(time back): t2
The solution (I skipped the gory details of solving, but you can verify by plugging the values back into the equations) is
Rate x = 2 miles/hour
(time there) = 1.5 hours
(time back) = 1 hour