Answer:
About 3 years Speedy Jet printers be guaranteed.
Step-by-step explanation:
Given : Quality control studies for Speedy Jet Computer Printers show the lifetime of the printer follows a normal distribution with
mean
and standard deviation 
If the company wishes to replace no more than 10% of the printers.
To find : How long should Speedy Jet printers be guaranteed ?
Solution :
Using Z- table,
Z value corresponding to 10% or 0.10 = -1.28.
Applying z-score formula,

The value of x is given by,

Substitute the values,



So, approx 3 years.
Therefore, About 3 years Speedy Jet printers be guaranteed.
We are given a concave spherical mirror with the following dimensions:
Radius = 60 cm; D o = 30 cm
Height = 6 cm; h o = 6 cm
First, we need to know the focal length, f, of the object (this should be given). Then we can use the following formulas for calculation:
Assume f = 10 cm
1/ f = 1 /d o + 1 / d i
1 / 10 = 1 / 30 + 1 / d i
d i = 15 cm
Then, calculate for h i:
h i / h o = - d i / d o
h i / 6 = - 15 / 30
h i = - 3 cm
Therefore, the distance of the object from the mirror is 3 centimeters. The negative sign means it is "inverted".
I think the answer would be 7.5 hours or 4 hours,not so sure which one exactly
0.22% shrinkage as a percent of sales.
To calculate shrinkage you subtract the physical inventory value from the book value.
245,000-237,000 = 800
The shrinkage was $800. To find the shrinkage as a percent of sales take the shrinkage value and divide it by the sales value to get shrinkage as a percentage of sales.
800 / 360,000 = 0.0022....
Multiply Decimal by 100 to get the percentage
100 * 0.0022.... = 0.22%