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
Charra [1.4K]
2 years ago
10

A particular battery claims to have a mean life of 400 hours with a standard deviation of 30 hours. Approximately what percent o

f the batteries will last more than 420 hours?
Mathematics
1 answer:
Svetach [21]2 years ago
3 0

Using the normal distribution, it is found that 25.14% of the batteries will last more than 420 hours.

<h3>Normal Probability Distribution</h3>

The z-score of a measure X of a normally distributed variable with mean \mu and standard deviation \sigma is given by:

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

  • The z-score measures how many standard deviations the measure is above or below the mean.
  • Looking at the z-score table, the p-value associated with this z-score is found, which is the percentile of X.

In this problem, we have that the mean and the standard deviation are given, respectively, by:

\mu = 400, \sigma = 30.

The proportion of the batteries will last more than 420 hours is <u>one subtracted by the p-value of Z when X = 420</u>, hence:

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

Z = \frac{420 - 400}{30}

Z = 0.67

Z = 0.67 has a p-value of 0.7486.

1 - 0.7486 = 0.2514.

0.2514 = 25.14% of the batteries will last more than 420 hours.

More can be learned about the normal distribution at brainly.com/question/24663213

#SPJ1

You might be interested in
To celebrate his soccer team's last game of the season, Grayson is making 4 batches of
s2008m [1.1K]

multiply 500 by 4 to know how much is needed in grams first

500×4 = 2000

convert 2000grams to kilograms

since 1000grams make 1 kilograms....then divide 2000 by 1000

which would give you 2000/1000

answer = 2kg of sugar

8 0
3 years ago
1 point
ludmilkaskok [199]
18n+4.4m I don’t know if this is right but I don’t understand the information you gave me because the numbers are scrambled
6 0
3 years ago
Read 2 more answers
3.
Lynna [10]

Answer:

the answer is B {(0,-4),(2,6)(,4,16)

happy to help

3 0
3 years ago
(Please correct answers only) (Will mark brainliest)
sergij07 [2.7K]
The answer is B., valid because people were chosen randomly
This would make it a valid survey
Hope this helps!
;3
8 0
3 years ago
Read 2 more answers
Can someone plss help me
puteri [66]
0/3 is the same thing as 0, so write those nxt to each other. Then 1/3, 2/3. Lastly 3/3 is the same as 1, so write those nxt to each other.
7 0
3 years ago
Other questions:
  • The dollar value v (t) of a certain car model that is t
    11·1 answer
  • On a coordinate plane, a triangle has points A prime (1, 2), B prime (3, negative 3), C prime (negative 1, negative 3). Triangle
    7·2 answers
  • a triangle has sides that measure 4 units 6 units and 7.21 units what is the area of a circle with a circumference that equals t
    11·1 answer
  • Rashid needs to by someone to build a box he must calculate the surface area of the box. How much wood does he need to buy
    11·1 answer
  • Vertical angles must: check all that apply
    14·1 answer
  • When the velocity v of an object is very​ large, the magnitude of the force due to air resistance is proportional to v squared w
    11·1 answer
  • Rewrite x^2 + 6x − 1 = 0 in the form (x + a)^2 = k, where a and k are constants. What is k?
    5·1 answer
  • A square picture in a magazine has an area of 27 square inches. What is the length of each side of the picture?
    8·1 answer
  • Please help!!!!!!!!!​
    15·1 answer
  • Which letter is at position (2 , -7)?
    14·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!