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
andre [41]
3 years ago
8

The lifetime of lightbulbs that are advertised to last for 4000 hours are normally distributed with a mean of 4250 hours and a s

tandard deviation of 300 hours. What is the probability that a bulb lasts longer than advertised
Mathematics
1 answer:
kobusy [5.1K]3 years ago
6 0

Answer:

79.67% probability that a bulb lasts longer than advertised

Step-by-step explanation:

Problems of normally distributed samples are solved using the z-score formula.

In a set with mean \mu and standard deviation \sigma, the zscore of a measure X is given by:

Z = \frac{X - \mu}{\sigma}

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.

In this problem, we have that:

\mu = 4250, \sigma = 300

What is the probability that a bulb lasts longer than advertised?

This is 1 subtracted by the pvalue of Z when X = 4000. So

Z = \frac{X - \mu}{\sigma}

Z = \frac{4000 - 4250}{300}

Z = -0.83

Z = -0.83 has a pvalue of 0.2033

1 - 0.2033 = 0.7967

79.67% probability that a bulb lasts longer than advertised

You might be interested in
Sxyz + 10x2y + 15 x y z²​
soldi70 [24.7K]
I can answer it but is the “S” supposed to be an integral?
8 0
2 years ago
50 divided by 70 pluse 10
jok3333 [9.3K]
50:70+10=\dfrac{50}{70}+10=\dfrac{5}{7}+10=\boxed{10\frac{5}{7}}
7 0
3 years ago
Read 2 more answers
Given: AB=CD, BD=DE<br> Prove: AD=CE
labwork [276]

This question is incomplete. Can you maybe add more information?

3 0
3 years ago
Read 2 more answers
Find the value of x for mAB=34 and mCD=25 (The figure is not drawn to scale.)
Alexus [3.1K]
<h3>Answer:   29.5 degrees</h3>

==============================================

Explanation:

Add up the arc measures and divide by 2 to get the angle formed by the two chords.

angle AOB = (arc AB + arc CD)/2

angle AOB = (34 + 25)/2

angle AOB = 59/2

angle AOB = 29.5 degrees

3 0
2 years ago
Read 2 more answers
I need help please i dont know
lesantik [10]

Answer:

round to the nerest hundered

Step-by-step explanation:

8 0
3 years ago
Other questions:
  • How do you find the equation that is perpendicular to 2x-5y=20, passing through the point (7,-8)?
    15·1 answer
  • 2x-y=-6<br>3x-4y=-4<br>Solve using elimination and then substitution
    15·1 answer
  • Help giving brainiest
    9·1 answer
  • An auditorium has 644 seats each row has 23 seats I mean how many rows are in the auditorium use estimation to show that your an
    11·1 answer
  • Twenty-four thousandths as a decimal
    7·2 answers
  • Naomi has a neon tetra fish and a guinea pig. The fish is 25 milliliters long. The guinea pig is 25 centimeters long. What is th
    5·1 answer
  • Jonah’s restaurant bill comes to $50.65, and he leaves a 20% tip, then pay 7.25%tax of the original bill. What is Jonah’s total
    12·2 answers
  • Help me Science Question
    11·1 answer
  • It costs $50 per hour to rent a jet ski. The total cost of a jet ski rental includes a flat fee plus an hourly fee. After 5 hour
    5·1 answer
  • PLEASE ANSWER AS FAST AS POSSIBLE PLEASE! I WILL MARK BRAINLIEST!
    12·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!