Question

Reading proficiency: An educator wants to construct a
98% confidence interval for the proportion of

elementary schoolchildren in Colorado who are proficient in
reading.

a. (1pt) The results of a recent statewide test suggested that the
proportion is 0.70. Using this

estimate, what sample size is needed so that the confidence
interval will have a margin of error

of 0.05?

b. (1pt) Estimate the sample size needed if no estimate of p is
available.

c. (2pt) If the educator wanted to estimate the proportion in the
entire United States rather than

in Colorado, would the necessary sample size be larger, smaller, or
about the same? Explain using complete sentences

Answer #1

**Solution:**

The data represent reading proficiency

a)

The sample size is,

From the standard normal table ,the z-critical value at 98% confidence is 2.33

The information represent, and for finding sample size.

b)

The sample size is,

From the standard normal table ,the z-critical value at 98% confidence is 2.33

The information represent, and for finding sample size.

c)

If the educator wanted to estimate proportion in the entire united states rather than in Colorado,the necessary sample size is larger due to entire united states population.

Reading proficiency: An educator wants to construct a 98%
confidence interval for the proportion of elementary school
children in Colorado who are proficient in reading.
(a) The results of a recent statewide test suggested that the
proportion is 0.61 Using this estimate, what sample size is needed
so that the confidence interval will have a margin of error of
0.03?

Reading proficiency: An educator wants to construct a 99%
confidence interval for the proportion
of elementary school children in Colorado who are proficient in
reading.
(b) Estimate the sample size needed if no estimate of P is
available.
A sample of __ elementary school children is needed to obtain a
99% confidence interval
with a margin of error of 0.03.

Surgical complications: A medical researcher wants to construct
a 98% confidence interval for the proportion of knee replacement
surgeries that result in complications.
(a) An article in a medical journal suggested that approximately
20% of such operations result in complications. Using this
estimate, what sample size is needed so that the confidence
interval will have a margin of error of 0.08?
A sample of__?/ operations is needed to obtain a 98% confidence
interval with a margin of error of 0.08...

"Call me: A sociologist wants to construct a 95% confidence
interval for the proportion of children aged 8–12 living in NewYork
who own a cell phone.a. A survey by the National Consumers League
estimated the nationwide proportion to be 0.56. Using this
estimate, what sample size is needed so that the confidence
interval will have a margin of error of 0.02?b. Estimate the sample
size needed if no estimate of p is31. Changing jobs: A sociologist
sampled 200 people who...

Surgical complications: A medical researcher
wants to construct a 98% confidence interval for the proportion of
knee replacement surgeries that result in complications.
) Estimate the sample size needed if no estimate of
p
is available.
A sample of __operations is needed
to obtain a 98%confidence interval with a margin of error of 0.08
when no estimate of p is available.

A researcher wants to construct a 95% confidence interval for
the proportion of elementary school students in Seward County who
receive free or reduced-price school lunches. What sample size is
needed so that the confidence interval will have a margin of error
of 0.03?

How's the economy? A pollster wants to construct a 95 %
confidence interval for the proportion of adults who believe that
economic conditions are getting better.
(a) A poll taken in July 2010 estimates this proportion to be
0.41 . Using this estimate, what sample size is needed so that the
confidence interval will have a margin of error of 0.02 ?
(b) Estimate the sample size needed if no estimate of p is
available. Part 1 of 2
(a)...

A sociologist wants to construct a 96% confidence interval for
the proportion of children aged 5 – 11 living in New York who own
cell phones.
a) A survey by Mediamark Research and Intelligence estimated the
nationwide proportion to be 0.20. Using this estimate, what sample
size is needed so that the confidence interval will have a margin
of error of 0.02?
b) Estimate the sample size needed if no estimate of the nationwide
proportion is given.

How's the economy? A pollster wants to construct a 99.5%
confidence interval for the proportion of
adults who believe that economic conditions are getting better.
Part: 0 / 20 of 2 Parts Complete
Part 1 of 2
(a) A poll taken in July 2010 estimates this proportion to be 0.37.
Using this estimate,
what sample size is needed so that the confidence interval will
have a margin of error of 0.03?
A sample of __ adults is needed to obtain...

How's the economy? A pollster wants to construct a 99.5%
confidence interval for the proportion of
adults who believe that economic conditions are getting better.
b) Estimate the sample size needed if no estimate of P is
available.
A sample of _ adults is needed to obtain a 99.5 confidence
interval with a margin of error of 0.03.

ADVERTISEMENT

Get Answers For Free

Most questions answered within 1 hours.

ADVERTISEMENT

asked 14 minutes ago

asked 1 hour ago

asked 1 hour ago

asked 1 hour ago

asked 1 hour ago

asked 1 hour ago

asked 1 hour ago

asked 1 hour ago

asked 1 hour ago

asked 1 hour ago

asked 1 hour ago

asked 2 hours ago