Answer:
345 sq. ft
Step-by-step explanation:
You know that the area is the length times the width. Simply plug in values to your equation:
A = l * w
A = 23 * 15
A = 345
The area is 345 square feet.
Answer:
20.
Step-by-step explanation:
P(5,3) = 5! / 3!
= (5*4*3*2*1) / (3*2*1)
= 20.
Answer:
21
Step-by-step explanation:
Using<em> Simple Random Sampling</em>, we can estimate the sample size by the formula
where
n = sample size
Z = the z-score corresponding to the confidence level 99.5%
S = the assumed standard deviation = 3 seconds
e = margin of error = 2 seconds
<em>It is worth noticing that the higher the confidence level, the larger the sample should be.
</em>
The z-score corresponding to a confidence level of 99.5% can be obtained either with a table or the computer and equals
Z = 3.023
Replacing the values in our formula
So the size of the sample should be at least 21.
Well they give you the equation and they want you to solve for time given that you know the amount of water in the tank. They tell you T=274 and that
T=450-8m so using the value T=274 in the equation to the left gives you:
274=450-8m subtract 450 from both sides
-176=-8m divide both sides by -8
22=m
So 22 minutes have passed when there is 274L remaining...
-7.
5x-3 = -15
-15-4\4= -16
-16 + 9 = -7