I’m pretty sure $1,800 Because if you subtract 660 by 470 you get 190 and it you multiply 190 by 6 years you get 1140 and if you add 1140 and 660 you get 1,800
Answer:
The statement that "the margin of error was given as
percentage points" means that the population proportion is estimated to be with a certain level of confidence, within the interval
; where
is likely to contain the true population percentage of people that prefer chocolate pie.
Step-by-step explanation:
The margin of error for proportions is given by the following formula:

Where:
is the critical value that corresponds to the confidence level; the confidence level being
,
is the sample's proportion of successes,
is the size of the sample.
In this exercise we have that
and that the margin of error is 0.05.
Therefore if we replace in the formula to calculate the confidence interval we get:

Which means that the true population proportion is estimated to be, with a certain confidence level, within the interval (0.09, 0.19).
<span>Standard deviation for mean of n objects = (square root n) x s.d. for one
object.
So you need (2.8/0.5)^2 or around 32.</span>