1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
sasho [114]
3 years ago
15

A certain brand of flood lamps has a lifetime that is normally distributed with a mean of 3,750 hours and a standard deviation o

f 300 hours. SKETCH
a.What is the probability that a lamp will last for more than 4,000 hours?
b.What is the probability that a lamp will last less than 3,000 hours?
c.What lifetime should the manufacturer advertise for these lamps in order that only 4% of the lamps will burn out before the advertised lifetime?
Mathematics
1 answer:
vesna_86 [32]3 years ago
7 0
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>
You might be interested in
Who can find the solution for this????<br><br> 4x=6(x-4)
Elenna [48]
4x = 6(x-4)
4x = 6x - 24
-2x = -24
x = 12
3 0
3 years ago
Read 2 more answers
I need help with this question. 20 points ton the person who can answer the question and make it make sense.
Law Incorporation [45]

Answer:

Because if they werent the messerue ments would be screwed and u would not be able to answer some questions

Step-by-step explanation:

also it makes a right triangle if equal

5 0
3 years ago
Help please I really need help<br> :)
Firdavs [7]

Answer:

Solution given:

For 1st

x²=71

For x=±\sqrt{71}

and

For 2nd

x³=71

For x=±\sqrt[3]{71}

So answer is:

In first row

<u>Solution to x²=71</u>

In second row

<u>Solution to </u><u>x³</u><u>=71</u>

In third row

<u>neither</u>

In forth row

<u>Solution to x³=71</u>

6 0
2 years ago
Heeeeeeeeeeeeelp thx
olga nikolaevna [1]
You would do 64 divided by 6. You would divide it by 6 because it’s himself AND 5 friends. This would get you to 60. So now each friend has ten. Their would be four left over. So now Nick had 14 cards for himself.
6 0
2 years ago
Simplify 7/8 divided by 8
meriva

Answer:

0.109375

Step-by-step explanation:

7/8 divided by 8 will be 0.109375

3 0
3 years ago
Read 2 more answers
Other questions:
  • What is the range data set of 34,36,52,49,47,34,4051?
    5·1 answer
  • Math Homework Help
    13·1 answer
  • Marcus works as a salesman at a car dealership. He is paid a base salary of $1,268.24 each month, and he receives a commission o
    14·1 answer
  • My square orchid garden abuts my house so that the house itself forms the northern boundary. The fencing for the southern bounda
    15·1 answer
  • PLEASE HELP, WILL MARK BRAINLIEST
    13·1 answer
  • Please answer all 3 questions! I provided them in pictures.
    6·1 answer
  • 20 POINTS !! PLEASE ANSWER THIS QUESTION !! WILL GIVE BRAINLIEST !!
    5·2 answers
  • Apples are on sale at four different grocery stores. Which store offers the
    10·1 answer
  • 6/3 + ( -1/6) =<br>I dont know the answer help please​
    6·1 answer
  • Solve |x| &gt; -9.<br><br> 1. no solution<br> 2. all reals<br> 3. {x | x &lt; -9 or x &gt; 9}
    7·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!