Answer:
±1, ±2, ±7, ±14
Step-by-step explanation:
The area of a parallelogram is the base times the height so:
A=bh, in this case:
A=hx
x=A/h, we are told that A=120mm^2 and h=10mm so
x=120mm^2/10mm
x=12mm
Why not look up "standard deviation" yourself, to be sure? But yes, the std. dev. is the sqrt of the variance.
Answer:
a. Fred's margin of error is larger than Ted's.
Step-by-step explanation:
Margin of error of a confidence interval:

In which z is related to the confidence level(the higher the confidence level the larger the value of z)
is the standard deviation of the population and n is the size of the sample.
From this, we have that:
A higher confidence level leads to a larger margin of error.
A larger sample size leads to a smaller margin of error.
In this question:
Same confidence level.
Fred's sample is smaller, so his margin of error will be larger.
The correct answer is given by option a.
So you have 318/2580 (since the top is the amount of money they use for food and the bottom is the total). You will want to divide it into 2 so 318/2 and 2580/2. Then you will get 159/1290. The divide 159/1290 with 3. So you will get 52/430. It may seem that you will need to divide 430 with 52 now. Once you get that, you will get the decimal 0.123255814. (I used a calculator). Then Move the decimal twice to the right to make that whole percentage. You will get 12 as you whole number (Ignoring the fact you have 3255814 as your remaining.). So the answer for that is….
12%!!