Given that mean=3750 hours and standard deviation is 300:
Then:
<span>a. The probability that a lamp will last for more than 4,000 hours?
P(x>4000)=1-P(x<4000)
but
P(x<4000)=P(z<Z)
where:
z=(x-</span>μ)/σ
z=(4000-3750)/300
z=0.833333
thus
P(x<4000)=P(z<0.8333)=0.7967
thus
P(x>4000)=1-0.7967=0.2033
<span>b.What is the probability that a lamp will last less than 3,000 hours?
P(x<3000)=P(z<Z)
Z=(3000-3750)/300
z=-2.5
thus
P(x<3000)=P(z<-2.5)=0.0062
c. </span><span>.What lifetime should the manufacturer advertise for these lamps in order that only 4% of the lamps will burn out before the advertised lifetime?
the life time will be found as follows:
let the value be x
the value of z corresponding to 0.04 is z=-2.65
thus
using the formula for z-score:
-2.65=(x-3750)/300
solving for x we get:
-750=x-3750
x=-750+3750
x=3000</span>
Answer: 70 ft
Step-by-step explanation:
Given
height of book is measured by the function is
when the book is thrown 
The height of the book is 
Here is the graph for this solution
Answer:
a. Yes. The difference is common and equal to $1750
b. $1750
c. $20000 was initial investment
d. This is linear equation with start point of 20000 and slope of 1750:
e. After another 10 years (on the top of 5 given) the investment will be:
- y = 1750*15 + 20000 = $46250
f. After 20 years the value of investment will be:
- y = 1750*20 + 20000 = $55000
Answer:
8720 Is the answer you just have to add them.
8000+720
