Question

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?

Answer #1

Let X be a mean life span of the items in years.

We want to find the 2% of the time their mean life will be less than C years.

P(X < C) = 0.02

The below 2% of the time their mean life is below C years.

We will solve this problem by standardising.

P(X < C) = P ((X - µ)/σ < (C – 12.8)/2.9) = P(Z < (C – 12.8)/2.9)

P(Z < (C – 12.8)/2.9) = 0.02

The Z score to corresponding area is 0.02 is -2.05(using statistical table).

NORM.S.INV(0.02) = -2.05375 ………….. (Using Excel fuction)

(C – 12.8)/2.9= -2.05

C = -2.05*2.9 + 12.8

C = 6.855

If 5 items are picked at random, 2% of the time their mean life will be less than approximate 7 many years.

A manufacturer knows that their items have a normally
distributed lifespan, with a mean of 12.8 years, and standard
deviation of 2.4 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 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.

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 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 3.2 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 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.

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 11 years, and standard
deviation of 1.9 years.
The 4% of items with the shortest lifespan will last less than how
many years
show work

ADVERTISEMENT

Get Answers For Free

Most questions answered within 1 hours.

ADVERTISEMENT

asked 1 minute ago

asked 2 minutes ago

asked 9 minutes ago

asked 9 minutes ago

asked 21 minutes ago

asked 24 minutes ago

asked 31 minutes ago

asked 33 minutes ago

asked 37 minutes ago

asked 41 minutes ago

asked 41 minutes ago

asked 53 minutes ago