Question

A toy manufacturer wants to know how many new toys children buy each year. Assume a previous study found the standard deviation to be 1.5. She thinks the mean is 7.2 toys per year. What is the minimum sample size required to ensure that the estimate has an error of at most 0.1 at the 98% level of confidence?

Answer #1

Given that the standard deviation , =1.5 and margin of error, E=01 , hence by Z table given below Z score at 98 % confidence level is 2.33 Now by Minimum sample formula

Hence minimum sample required is 1222

We were unable to transcribe this image

N Z2 E2 2.332 1.52 0.12 48.8601 49

We were unable to transcribe this image

We were unable to transcribe this image

We were unable to transcribe this image

We were unable to transcribe this image

A toy manufacturer wants to know how many new toys children buy
each year. Assume a previous study found the standard deviation to
be 1.5. She thinks the mean is 6.9 toys per year. What is the
minimum sample size required to ensure that the estimate has an
error of at most 0.1 at the 80% level of confidence? Round your
answer up to the next integer.

A toy manufacturer wants to know how many new toys children buy
each year. Assume a previous study found the
variance to be 3.61. She thinks the mean is 9.3
toys per year. What is the minimum sample size required to ensure
that the estimate has an error of at most 0.12 at the 90% level of
confidence? Round your answer up to the next
integer.

A fashion designer wants to know how many new dresses women buy
each year. Assume a previous study found the variance to be 4. She
thinks the mean is 7 dresses per year. What is the minimum sample
size required to ensure that the estimate has an error of at most
0.11 at the 90% level of confidence? Round your answer up to the
next integer.

A fashion designer wants to know how many new dresses women buy
each year. Assume a previous study found the standard deviation to
be 1.4. She thinks the mean is 7.3 dresses per year. What is the
minimum sample size required to ensure that the estimate has an
error of at most 0.13 at the 90% level of confidence? Round your
answer up to the next integer.

PART ONE: A toy manufacturer wants to know how many new toys
children buy each year. A sample of 305 children was taken to study
their purchasing habits. Construct the 80% confidence interval for
the mean number of toys purchased each year if the sample mean was
found to be 7.6. Assume that the population standard deviation is
1.5. Round your answers to one decimal place.
PART TWO: Find the area under the standard normal curve between
z=−0.75z=−0.75 and z=1.83z=1.83....

A fashion designer wants to know how many new dresses women buy
each year. She thinks the mean is 6.6 dresses per year. Assume a
previous study found the variance to be 4. How large of a sample
would be required in order to estimate the mean number of dresses
bought per woman at the 98% confidence level with an error of at
most 0.09 dresses?

A toy company wants to know the mean number of new toys per
child bought each year. Marketing strategists at the toy company
collect data from the parents of 50 randomly selected children. The
sample mean is found to be 4.7 toys per child, and the sample
standard deviation is calculated to be 1.5 toys per child per
year.
Assume that the population standard deviation is unknown. What
is the upper bound for a 99% confidence interval? Group of answer...

A software developer wants to know how many new computer games
people buy each year. A sample of 2395 people was taken to study
their purchasing habits. Construct the 98% confidence interval for
the mean number of computer games purchased each year if the sample
mean was found to be 6.3. Assume that the population standard
deviation is 2.2. Round your answers to one decimal place.

A soft drink manufacturer wishes to know how many soft drinks
adults drink each week. They want to construct a 95% confidence
interval with an error of no more than 0.08. A consultant has
informed them that a previous study found the mean to be 3.1 soft
drinks per week and found the variance to be 0.49. What is the
minimum sample size required to create the specified confidence
interval? Round your answer up to the next integer.

A soft drink manufacturer wishes to know how many soft drinks
adults drink each week. They want to construct a 85% confidence
interval with an error of no more than 0.06. A consultant has
informed them that a previous study found the mean to be 7.6 soft
drinks per week and found the variance to be 0.81. What is the
minimum sample size required to create the specified confidence
interval? Round your answer up to the next integer.

ADVERTISEMENT

Get Answers For Free

Most questions answered within 1 hours.

ADVERTISEMENT

asked 6 minutes ago

asked 14 minutes ago

asked 19 minutes ago

asked 24 minutes ago

asked 39 minutes ago

asked 41 minutes ago

asked 56 minutes ago

asked 1 hour ago

asked 1 hour ago

asked 1 hour ago

asked 1 hour ago

asked 1 hour ago