Question

A battery manufacturer finds that the life of its batteries are normally distributed with a mean of 32 months and a standard deviation of 5 months. Find the probability that a battery lasts more than 36 months. Round off to four decimal places.

Answer #1

Solution:

Given, X follows Normal distribution with,

= 32

= 5

Find P(a battery lasts more than 36 months)

= P(X > 36)

= P[(X - )/ > (36 - )/]

= P[Z > (36 - 32)/5]

= P[Z > 0.80]

= 1 - P[Z < 0.80]

= 1 - 0.7881 ( use z table)

= 0.2119

P(a battery lasts more than 36 months) is

**0.2119**

4. Find the standard deviation of the following discrete
probability distribution. Round off to two decimal places.
x P(x)
0 0.1
1 0.85
2 0.9-a
5. A die is rolled 7 times. Success is getting a 6. Find the
probability of getting three 6's. Round off to three decimal
places.
6. A light bulb manufacturer finds that the lifespan of its
products is normally distributed with a mean of 800 hours and a
standard deviation of 50. Find the probability...

Suppose the life of a particular brand of calculator battery is
approximately normally distributed with a mean of 85 hours and a
standard deviation of 11 hours. Complete parts a through c.
a. What is the probability that a single battery randomly
selected from the population will have a life between 80
and 90 hours?
P(80≤ overbar x≤90)= (Round to four decimal places as
needed.)
b. What is the probability that 4 randomly sampled batteries
from the population will have...

Suppose the life of a particular brand of calculator battery is
approximately normally distributed with a mean of
80 hours and a standard deviation of 11 hours. Complete parts a
through c.
a. What is the probability that a single battery randomly selected
from the population will have a life between
and hours?
75
85
P(75 ≤ x ≤ 85) = (Round to four decimal places as needed.)
b. What is the probability that randomly sampled batteries from the
population...

The life span of a battery is normally distributed, with a mean
of 2400 hours and a standard deviation of 50 hours. What percent of
batteries have a life span that is more than 2460 hours? Would it
be unusual for a battery to have a life span that is more than 2460
hours? Explain your reasoning.
What percent of batteries have a life span that is more than
2460 hours?
Approximately_______% of batteries have a life span that is...

Suppose the life of a particular brand of calculator battery is
approximately normally distributed with a mean of 75 hours and a
standard deviation of 9 hours. Complete parts a through c.
a. What is the probability that a single battery randomly
selected from the population will have a life between 70 and 80
hours? P(70 < or = x overbar < or = 80) = 0.4246 (Round
to four decimal places as needed.)
b. What is the probability that...

The life of a fully-charged cell phone battery is normally
distributed with a mean of 14 hours with a standard deviation of 3
hours. What is the probability that 25 batteries last less than 16
hours?

Suppose the life of a particular brand of calculator battery is
approximately normally distributed with a mean of 75 hours and a
standard deviation of 9 hours.
a. What is the probability that a single battery randomly
selected from the population will have a life between 70 and 80
hours? P(70less than or equalsx overbarless than or
equals80)equals nothing (Round to four decimal places as
needed.)

The life spans of batteries are normally distributed, with a
mean of 2000 hours and a standard deviation of 30 hours.
a. How would we know by looking at the graph, if the probability
of batteries with a life span of less 1900 hours is more or less
than 50%> Explain your answer. DO NOT show any
mathematical work.
b. What percent of batteries have a life span that is more than
2065 hours? Show work as in class.

The life of a certain AAA batteries is normally distributed with
a variance of 100 hours and mean of 550 hours. Find the probability
that a battery chosen at random will last no more than 568
hours

The life of a fully-charged cell phone battery is normally
distributed with a mean of 14 hours with a standard deviation of 3
hours. What is the probability that 25 batteries last at least 13
hours?

ADVERTISEMENT

Get Answers For Free

Most questions answered within 1 hours.

ADVERTISEMENT

asked 2 minutes ago

asked 2 minutes ago

asked 21 minutes ago

asked 31 minutes ago

asked 33 minutes ago

asked 41 minutes ago

asked 42 minutes ago

asked 45 minutes ago

asked 45 minutes ago

asked 58 minutes ago

asked 1 hour ago

asked 1 hour ago