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.
So to put them in intervals of 5 you would have:
70-74
75-79
80-84
85-89
90-94
95-99
In these intervals you would have:
70-74: 72
75-79: 78
80-84: 81
85-89: 86, 86, 87
90-94: 92, 92, 92
95-99: 98
The second interval is 75-79 where there is only one number. Therefore the frequency will be 1.
The correct answer is A. Hope this helps! :)
Answer:
24
Step by-step explanation:
6x=3x-1+13
common like terms (-1+13)
6x=3x+12
subtract 3x on both sides
3x=12
divide 3x on both sides
x=4
insert 4 into equation 6*4=24
3(4)-1+13=24
Answer:
parallelogram 's perimeter =2(8.2+6.5)
""" =2×14.7
... = 29.4
perimeter of triangle=7.2+6.1+9.6
""""" =22.9