The face dimensions are all the same, so the 3 lateral faces each have the same area. The lateral area is
3·(10 cm²) = 30 cm²
1x+3y=8
3x+2y=10
solve
multiply first equation by -3 and add to 2nd equation
-3x-9y=-24
<u>3x+2y=10 +</u>
0x-7y=-14
-7y=-14
divide by -7 both sides
y=2
sub back
x+3y=8
x+3(2)=8
x+6=8
minus 6
x=2
wow
both juices cost $2 per gallon
(a) A suitable probability app tells you the probability of being less than 17,900 or more than 18,100 is about 4.55%.
(b) We want to find σ² such that 2P((18100-18000)/σ) ≤ 0.01. We use a factor of 2 because we want to count deviations both above and below 100 feet from the mean altitude. A suitable probability app can tell you the z-score such that P(Z)≤0.005, so we need to compute σ² = (100/Z)² from that result. Doing so, we get σ² ≈ 1507.