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:
30%
Step-by-step explanation:
because you use %
so that is why i think but i am not sure
We can set up 2 equations given the information.
Let the price of advance ticket be represented by A and same day ticket by S
A + S = 50
20A + 40S = 1700
Solve for A in the first equation by subtracting S on both sides.
U will get A = 50 - S
Now substitute 50 - S for A in the second equation.
20 (50 - S) + 40S = 1700
1000 - 20S + 40S = 1700
20S = 700
S = 35
Same day ticket costs $35 and advance ticket costs $15
Answer:
(x-4)(x-3) hope this helps
Step-by-step explanation:
Answer:
Volume: 41.643
Surface area: 119.04 (nearest tenth... I don't know...sorry)
Step-by-step explanation:
I didn't know if you need volume or surface area so you got both!
