The keyword is "sum" which tells you x, y, and z are being added. One half of the sum means that the sum of the three numbers is going to be divided by 2.
x + y + z
------------
2
Profit = revenue - expenses
expenses : 125,000 + 6.50x
revenue : 9x
so to make a profit, ur revenue (income) has to be higher then ur expenses
revenue > expenses
A. ) 9x > 125,000 + 6.50x
9x - 6.50x > 125,000
2.5x > 125,000
x > 125,000 / 2.5
x > 50,000......so they would have to sell at least 50,001 devices to make a profit <==
B.) the cost of making 1 device is 10% more then the company predicted....10% more then 6.50.....6.50(1.10) = 7.15.....this is the new cost of making 1 device <==
9x > 125,000 + 7.15x ....this is the inequality with the 10% more added
9x - 7.15x > 125,000
1.85x > 125,000
x > 125,000 / 1.85
x > 67,567.5......so to make a profit, they would have to sell at least 67,568 devices to make a profit <==
Answer:
(22.12, 27.48)
Step-by-step explanation:
Given : Significance level : 
Sample size : n= 8 , which is a small sample (n<30), so we use t-test.
Critical values using t-distribution: 
Sample mean : 
Standard deviation : 
The confidence interval for population means is given by :-

i.e. 

Hence, the 95% confidence interval, assuming the times are normally distributed.= (22.12, 27.48)
Answer:
A slope of the line over the interval of [-6, -1] is ⅕ as illustrated in the graph above
Answer:
1.25 kg of icing sugar
3.75 kg of butter
3 kgs of caster sugar
2.75 kgs flour
25 eggs
125g baking powder
Step-by-step explanation:
300/12 x (weight of ingredient)