Profit = paid - supplies
Plug in the given values. We are finding out how much money he needs per room, if he is doing 4 rooms, and subtracting the supplies: 300 = 4n - 4*32.50
Simplify: 300 = 4n - 130
Add 130 to each side. 430 = 4n
Divide by 4 on each side: 107.50= n
300 = 4(107.50) - 130? True
This tells us he must be paid $107.50 to make $300 exactly. Anything larger than $107.51 and up will make more than $300.
Solution
To solve this addition of fractions we are gonna apply the fraction rule which is;
a/c + b/c = (a + b)/c
2/11 + 1/11 = (2 + 1)/11
= (2 + 1)/11 + 2/7
Now add the numerators 2 + 1
= (2 + 1)/11 + 2/7
= 3/11 + 2/7
Now we find the least common multiple
The least common multiple of 11 and 7 is 77.
But before that we cross multiply the numerators.
3 * 7 = 21
2 * 11 = 22
Now the ajustes fraction is;
21/77 + 22/77
Apply the fraction rule which is;
a/c + b/c = (a + b)/c
= (21 + 22)/77
Now we add the numerators.
43/77
Therefore the answer in fraction is 43/77 and in decimal form it is 0.55841
The 68-95-99.7 rule tells us 68% of the probability is between -1 standard deviation and +1 standard deviation from the mean. So we expect 75% corresponds to slightly more than 1 standard deviation.
Usually the unit normal tables don't report the area between -σ and σ but instead a cumulative probability, the area between -∞ and σ. 75% corresponds to 37.5% in each half so a cumulative probability of 50%+37.5%=87.5%. We look that up in the normal table and get σ=1.15.
So we expect 75% of normally distributed data to fall within μ-1.15σ and μ+1.15σ
That's 288.6 - 1.15(21.2) to 288.6 + 1.15(21.2)
Answer: 264.22 to 312.98
