Answer:
x = -30
Step-by-step explanation:
x - (-10) = -20
Subtracting a negative is adding
x+10 = -20
Subtract 10 from each side to isolate x
x+10-10 = -20-10
x = -30
Let x be the required waranty period, then
P(X < x) = P(z < (x - 12)/(8/12)) = 1 - 0.067 = 0.933
P(z < 12(x - 12)/8) = P(z < 1.498)
12(x - 12)/8 = 1.498
x - 12 = 8(1.498) / 12 = 0.9987
x = 12 - 0.9987 = 11
Therefore, they should waranty for 11 years so that no more than 6.7% fail within that time.
cost of production = %13
Let the price be p, then
revenue less price of failed iron = p - 0.067(13) = p - 0.871
Profit = p - 0.871 - 13 = 5
p - 13.871 = 5
p = 5 + 13.871 = 18.871
Therefore, the should charge $18.87 per waffle iron.
1.) To find the surface area, we want to find the area of each side, then add them all up together:
Area of base=lwA=(5)(5)A=25 cm²
Area of triangle=1/2bhA=(1/2)(5)(12.5)A=31.25 cm²
Since the 4 triangles have the same area, we can multiply the area we found by 4 and then add the area of the square:
SA=(4)(31.25) + 25SA=125+25SA=150 cm²
2.) <span>To find the volume use the formula:
V=(1/3)lwh
V=(1/3)(5)(5)(12.5)
V=104.167 cm^3</span>
$256.75
Add $178 + $98.25= $276.25
Then $276.25 - $19.50 = $256.75
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