1a:
580 - (580 × .1) - 20
580 - (58) - 20
522 - 20
502
1b:
990 - (990 × .25) - 20
990 - (247.5) - 20
742.5 - 20
722.5
I'm not sure how to solve #2.
Answer:
(6/5) mph
Step-by-step explanation:
Answer:
The bill size can be considered usual.
Step-by-step explanation:
Mean (μ) = $108.43
Standard deviation (σ) = $36.98
Now, consider the distribution to be normal distribution :

Now, finding values of z-score from the table. We get,
P(Z > 1.75) = 0.9599
⇒ 95.99%
So, only 4.01 % of the people in the city wastes water.
Hence, the bill size can be considered usual.
Step-by-step explanation:
2x + 2y = 184 ---- eqn 1
y = 184 - 2x / 2
y = 92 - x ---- eqn 2