Answer:
B. Larger sample size and lower confidence level
Step-by-step explanation:
The margin of error of a confidence interval is given by the following formula:

In which
is the standard deviation of the population and n is the size of the sample.
z is related to the confidence level. The higher the confidence level, the higher the value of Z.
So, the margin of error is direct proportion to the confidence level and inverse proportional to the sample size.
We want to decrease the margin of error.
So the correct answer is:
B. Larger sample size and lower confidence level
5 bags with 6 flower bulbs in each equals 30.
He planted all but 3
30-3=27
Leonard planted 27 bulbs
Given:

To get rid of the fraction, we can multiply both sides by the denominator, which is 3. This will cancel the fraction:

We are left with:

Remark
A cube has six sides, all of them equal. The formula for 1 side is s^2. The formula for all six = 6s^2.
Step One
Find the surface area of the larger cube.
Area = 6 *s^2
s = 15
Area = 6 *15^2
Area = 6 * 225
Area = 1350
Step Two
Find the area of the smaller cube
Area = 6s^2
Area = 6 * 12^2
Area = 6 * 144
Area = 864
Step Three
Find the difference
Area1 - Area2 = difference
1350 - 864 = 486
The difference is area = 486 units^2 <<<<< Answer
There is a slightly shorter way. Take out the common factor of 6
Difference = 6 * (15^2 - 12^2)
Difference = 6 * (225 - 144)
Difference = 6 * (81)
Difference = 486