Allen's hummingbird (Selasphorus sasin) has been studied by zoologist Bill Alther. Suppose a small group of 11 Allen's hummingbirds has been under study in Arizona. The average weight for these birds is x = 3.15 grams. Based on previous studies, we can assume that the weights of Allen's hummingbirds have a normal distribution, with = 0.36 gram.(a) Find an 80% confidence interval for the average weights of Allen's hummingbirds in the study region. What is the margin of error? (Round your answers to two decimal places.)

lower limit
upper limit
margin of error

(b) What conditions are necessary for your calculations? (Select all that apply.)

uniform distribution of weights is knownnormal distribution of weightsn is large is unknown (c) Interpret your results in the context of this problem.We are 20% confident that the true average weight of Allen's hummingbirds falls within this interval. We are 80% confident that the true average weight of Allen's hummingbirds falls within this interval. The probability that this interval contains the true average weight of Allen's hummingbirds is 0.80.The probability that this interval contains the true average weight of Allen's hummingbirds is 0.20. (d) Find the sample size necessary for an 80% confidence level with a maximal margin of error E = 0.10 for the mean weights of the hummingbirds. (Round up to the nearest whole number.) hummingbirds

2.

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Allen's hummingbird (Selasphorus sasin) has been studied by zoologist Bill Alther.Suppose a small group of12Allen's hummingbirds has been under study in Arizona. The average weight for these birds isx= 3.15 grams.Based on previous studies, we can assume that the weights of Allen's hummingbirds have a normal distribution, with=0.34gram.

When finding an 80% confidence interval, what is the critical value for confidence level? (Give your answer to two decimal places.)

z_c=

(a)

Find an 80% confidence interval for the average weights of Allen's hummingbirds in the study region. What is the margin of error? (Round your answers to two decimal places.)

lower limitupper limitmargin of error

(b)

What conditions are necessary for your calculations? (Select all that apply.)

is knownis unknownuniform distribution of weightsnormal distribution of weightsnis large

(c)

Interpret your results in the context of this problem.

The probability that this interval contains the true average weight of Allen's hummingbirds is 0.80.We are 80% confident that the true average weight of Allen's hummingbirds falls within this interval. We are 20% confident that the true average weight of Allen's hummingbirds falls within this interval.The probability that this interval contains the true average weight of Allen's hummingbirds is 0.20.

(d)

Which equation is used to find the sample sizenfor estimatingwhenis known?

n=

zE

n=

zE

	2

n=

z

E

	2

n=

z E

Find the sample size necessary for an 80% confidence level with a maximal margin of errorE=0.12for the mean weights of the hummingbirds. (Round up to the nearest whole number.)

hummingbirds

3.

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Allen's hummingbird (Selasphorus sasin) has been studied by zoologist Bill Alther.Suppose a small group of16Allen's hummingbirds has been under study in Arizona. The average weight for these birds isx= 3.15 grams.Based on previous studies, we can assume that the weights of Allen's hummingbirds have a normal distribution, with=0.28gram.

(a)

Find an 80% confidence interval for the average weights of Allen's hummingbirds in the study region. What is the margin of error? (Round your answers to two decimal places.)

lower limitupper limitmargin of error

(b)

What conditions are necessary for your calculations? (Select all that apply.)

is knownnis largeis unknownuniform distribution of weightsnormal distribution of weights

(c)

Interpret your results in the context of this problem.

The probability that this interval contains the true average weight of Allen's hummingbirds is 0.80.We are 80% confident that the true average weight of Allen's hummingbirds falls within this interval. The probability that this interval contains the true average weight of Allen's hummingbirds is 0.20.We are 20% confident that the true average weight of Allen's hummingbirds falls within this interval.

(d)

Find the sample size necessary for an 80% confidence level with a maximal margin of errorE=0.09for the mean weights of the hummingbirds. (Round up to the nearest whole number.)

hummingbirds

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Overproduction of uric acid in the body can be an indication of cell breakdown. This may be an advance indication of illness such as gout, leukemia, or lymphoma.Over a period of months, an adult male patient has takennineblood tests for uric acid. The mean concentration wasx=5.32mg/dl.The distribution of uric acid in healthy adult males can be assumed to be normal, with=1.83mg/dl.

(a)

Find a 95% confidence interval for the population mean concentration of uric acid in this patient's blood. What is the margin of error? (Round your answers to two decimal places.)

lower limitupper limitmargin of error

(b)

What conditions are necessary for your calculations? (Select all that apply.)

normal distribution of uric acidis unknownuniform distribution of uric acidnis largeis known

(c)

Interpret your results in the context of this problem.

The probability that this interval contains the true average uric acid level for this patient is 0.05.The probability that this interval contains the true average uric acid level for this patient is 0.95. We are 5% confident that the true uric acid level for this patient falls within this interval.We are 95% confident that the true uric acid level for this patient falls within this interval.

(d)

Find the sample size necessary for a 95% confidence level with maximal margin of errorE=1.10for the mean concentration of uric acid in this patient's blood. (Round your answer up to the nearest whole number.)

blood tests

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Total plasma volume is important in determining the required plasma component in blood replacement therapy for a person undergoing surgery. Plasma volume is influenced by the overall health and physical activity of an individual. Suppose that a random sample of47male firefighters are tested and that they have a plasma volume sample mean ofx= 37.5 ml/kg(milliliters plasma per kilogram body weight). Assume that=7.30ml/kgfor the distribution of blood plasma.(a) Find a 99% confidence interval for the population mean blood plasma volume in male firefighters. What is the margin of error? (Round your answers to two decimal places.)

lower limit
upper limit
margin of error

(b) What conditions are necessary for your calculations? (Select all that apply.)nis largeis unknownis knownthe distribution of volumes is normalthe distribution of volumes is uniform

(c) Interpret your results in the context of this problem.We are 1% confident that the true average blood plasma volume in male firefighters falls within this interval.We are 99% confident that the true average blood plasma volume in male firefighters falls within this interval. The probability that this interval contains the true average blood plasma volume in male firefighters is 0.99.The probability that this interval contains the true average blood plasma volume in male firefighters is 0.01.

(d) Find the sample size necessary for a 99% confidence level with maximal margin of errorE=2.60for the mean plasma volume in male firefighters. (Round up to the nearest whole number.) male firefighters

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Total plasma volume is important in determining the required plasma component in blood replacement therapy for a person undergoing surgery. Plasma volume is influenced by the overall health and physical activity of an individual. Suppose that a random sample of45male firefighters are tested and that they have a plasma volume sample mean ofx= 37.5 ml/kg(milliliters plasma per kilogram body weight). Assume that=7.90ml/kgfor the distribution of blood plasma.

When finding an 99% confidence interval, what is the critical value for confidence level? (Give your answer to two decimal places.)

z_c=

(a)

Find a 99% confidence interval for the population mean blood plasma volume in male firefighters. What is the margin of error? (Round your answers to two decimal places.)

lower limitupper limitmargin of error

(b)

What conditions are necessary for your calculations? (Select all that apply.)

the distribution of volumes is normalis knownthe distribution of volumes is uniformnis largeis unknown

(c)

Interpret your results in the context of this problem.

The probability that this interval contains the true average blood plasma volume in male firefighters is 0.01.We are 1% confident that the true average blood plasma volume in male firefighters falls within this interval. The probability that this interval contains the true average blood plasma volume in male firefighters is 0.99.We are 99% confident that the true average blood plasma volume in male firefighters falls within this interval.

(d)

Which equation is used to find the sample sizenfor estimatingwhenis known?

n=

zcE

n=

z_c

E

	2

n=

zc E

n=

z_cE

	2

Find the sample size necessary for a 99% confidence level with maximal margin of errorE=2.20for the mean plasma volume in male firefighters. (Round up to the nearest whole number.)

male firefighters

7.

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Total plasma volume is important in determining the required plasma component in blood replacement therapy for a person undergoing surgery. Plasma volume is influenced by the overall health and physical activity of an individual. Suppose that a random sample of50male firefighters are tested and that they have a plasma volume sample mean ofx= 37.5 ml/kg(milliliters plasma per kilogram body weight). Assume that=7.90ml/kgfor the distribution of blood plasma.

(a)

Find a 99% confidence interval for the population mean blood plasma volume in male firefighters. What is the margin of error? (Round your answers to two decimal places.)

lower limitupper limitmargin of error

(b)

What conditions are necessary for your calculations? (Select all that apply.)

nis largethe distribution of volumes is normalis unknownthe distribution of volumes is uniformis known

(c)

Interpret your results in the context of this problem.

We are 99% confident that the true average blood plasma volume in male firefighters falls within this interval.The probability that this interval contains the true average blood plasma volume in male firefighters is 0.01. We are 1% confident that the true average blood plasma volume in male firefighters falls within this interval.The probability that this interval contains the true average blood plasma volume in male firefighters is 0.99.

(d)

Find the sample size necessary for a 99% confidence level with maximal margin of errorE=2.20for the mean plasma volume in male firefighters. (Round up to the nearest whole number.)

male firefighters

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Total plasma volume is important in determining the required plasma component in blood replacement therapy for a person undergoing surgery. Plasma volume is influenced by the overall health and physical activity of an individual. Suppose that a random sample of46male firefighters are tested and that they have a plasma volume sample mean ofx= 37.5 ml/kg(milliliters plasma per kilogram body weight). Assume that=7.60ml/kgfor the distribution of blood plasma.

(a)

Find a 99% confidence interval for the population mean blood plasma volume in male firefighters. What is the margin of error? (Round your answers to two decimal places.)

lower limitupper limitmargin of error

(b)

What conditions are necessary for your calculations? (Select all that apply.)

is knownthe distribution of volumes is uniformnis largeis unknownthe distribution of volumes is normal

(c)

Interpret your results in the context of this problem.

The probability that this interval contains the true average blood plasma volume in male firefighters is 0.99.We are 99% confident that the true average blood plasma volume in male firefighters falls within this interval. We are 1% confident that the true average blood plasma volume in male firefighters falls within this interval.The probability that this interval contains the true average blood plasma volume in male firefighters is 0.01.

(d)

Find the sample size necessary for a 99% confidence level with maximal margin of errorE=2.20for the mean plasma volume in male firefighters. (Round up to the nearest whole number.)

male firefighters

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What price do farmers get for their watermelon crops? In the third week of July, a random sample of41farming regions gave a sample mean ofx= $6.88per 100 pounds of watermelon. Assume thatis known to be$1.92per 100 pounds.(a) Find a 90% confidence interval for the population mean price (per 100 pounds) that farmers in this region get for their watermelon crop. What is the margin of error? (Round your answers to two decimal places.)

lower limit	$
upper limit	$
margin of error	$

(b) Find the sample size necessary for a 90% confidence level with maximal error of estimateE=0.29for the mean price per 100 pounds of watermelon. (Round up to the nearest whole number.) farming regions (c) A farm brings 15 tons of watermelon to market. Find a 90% confidence interval for the population mean cash value of this crop. What is the margin of error?Hint:1 ton is 2000 pounds. (Round your answers to two decimal places.)

lower limit	$
upper limit	$
margin of error	$