Question

A manufacturer knows that their items have a normally
distributed lifespan, with a mean of 5 years, and standard
deviation of 0.7 years.

If 20 items are picked at random, 6% of the time their mean life
will be less than how many years?

Give your answer to one decimal place.

Answer #1

Solution :

Given that,

mean = = 5

standard deviation = = 0.7

Sample size = n = 20

_{}
=
/
n = 0.7 /
20 = 0.1565

Using standard normal table ,

P(Z < z) = 6%

P(Z < z) = 0.06

P(Z < -1.56) = 0.06

z = -1.56

Using z-score formula,

x = z *
_{}+
_{}

x = -1.56 * 0.1565 + 5 = 4.8

6% of the time their mean life will be less than is 4.8 years

A manufacturer knows that their items have a normally
distributed lifespan, with a mean of 3.2 years, and standard
deviation of 0.7 years. If 12 items are picked at random, 10% of
the time their mean life will be less than how many years? Give
your answer to one decimal place.

A manufacturer knows that their items have a normally
distributed lifespan, with a mean of 7.6 years, and standard
deviation of 2.1 years.
If 11 items are picked at random, 6% of the time their mean life
will be less than how many years?
Give your answer to one decimal place.

A manufacturer knows that their items have a normally
distributed lifespan, with a mean of 3.9 years, and standard
deviation of 1.2 years. If 7 items are picked at random, 5% of the
time their mean life will be less than how many years? Give your
answer to one decimal place.

A manufacturer knows that their items have a normally
distributed lifespan, with a mean of 4 years, and standard
deviation of 1.1 years. If 17 items are picked at random, 4% of the
time their mean life will be less than how many years? Give your
answer to one decimal place.

A manufacturer knows that their items have a normally
distributed lifespan, with a mean of 9.3 years, and standard
deviation of 2.7 years.
If 10 items are picked at random, 7% of the time their mean life
will be less than how many years?
Give your answer to one decimal place.

A manufacturer knows that their items have a normally
distributed lifespan, with a mean of 12.8 years, and standard
deviation of 2.4 years. If 22 items are picked at random, 7% of the
time their mean life will be less than how many years? Give your
answer to one decimal place.

a manufacturer knows that their items have a normally
distributed lifespan, with a mean of 11.7 years, and standard
deviation of 0.7 years. if 6 items are picked at random, 10% of the
time their mean life will be less than how many years?

A manufacturer knows that their items have a normally
distributed lifespan, with a mean of 12.8 years, and standard
deviation of 2.9 years. If 5 items are picked at random, 2% of the
time their mean life will be less than how many years?

QUESTION PART A: A manufacturer knows that their items have a
normally distributed lifespan, with a mean of 6.6 years, and
standard deviation of 0.8 years.
If 22 items are picked at random, 6% of the time their mean life
will be less than how many years?
Give your answer to one decimal place.
QUESTION PART B: A particular fruit's weights are normally
distributed, with a mean of 679 grams and a standard deviation of
19 grams.
If you pick...

A manufacturer knows that their items have a normally
distributed lifespan, with a mean of 2.3 years, and standard
deviation of 0.6 years.
The 6% of items with the shortest lifespan will last less than how
many years?
Give your answer to one decimal place.

ADVERTISEMENT

Get Answers For Free

Most questions answered within 1 hours.

ADVERTISEMENT

asked 1 minute ago

asked 4 minutes ago

asked 11 minutes ago

asked 13 minutes ago

asked 17 minutes ago

asked 21 minutes ago

asked 21 minutes ago

asked 33 minutes ago

asked 34 minutes ago

asked 35 minutes ago

asked 51 minutes ago

asked 54 minutes ago