Question

The population standard deviation for the employee turnover of each department in a company is 3.7 employees. If we want to be 95% confident that the sample mean is within 1 employee of the true population mean, what is the minimum sample size that can be taken?

z 0.10 | z 0.05 | z 0.025 | z 0.01 | z 0.005 |

1.282 | 1.645 | 1.960 | 2.326 | 2.576 |

Use the table above for the z-score, and be sure to round up to the nearest integer.

Provide your answer below:

Answer #1

:

Solution

standard deviation =s = =3.7

Margin of error = E = 1

At 95% confidence level the z is ,

= 1 - 95% = 1 - 0.95 = 0.05

/ 2 = 0.05 / 2 = 0.025

Z/2 = Z0.025 = 1.96 ( Using z table ( see the 0.025 value in standard normal (z) table corresponding z value is 1.96 )

sample size = n = [Z/2* / E] 2

n = ( 1.96* 3.7 / 1 )2

n =52.59

Sample size = n =53

he population standard deviation for the heights of dogs, in
inches, in a city is 6.5 inches. If we want to be 95% confident
that the sample mean is within 2 inches of the true population
mean, what is the minimum sample size that can be taken? z0.10
z0.05 z0.04 z0.025 z0.01 z0.005 1.282 1.645 1.751 1.960 2.326 2.576
Use the table above for the z-score, and be sure to round up to the
nearest integer.

The population standard deviation for the heights of dogs, in
inches, in a city is 7.8 inches. If we want to be 95% confident
that the sample mean is within 2 inches of the true population
mean, what is the minimum sample size that can be taken?
z0.10
z0.05
z0.04
z0.025
z0.01
z0.005
1.282
1.645
1.751
1.960
2.326
2.576
Use the table above for the z-score, and be sure to round up to
the nearest integer.
Provide your answer below:

The population standard deviation for the heights of dogs in
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the sample mean is within 2 inches of the true population mean.
What is the minimum sample size that can be taken?
Z0.10
1.282
Z0.05
1.645
Z0.025
1.960
Z.0.01
2.326
Z0.005
2.576

The population standard deviation for the heights of dogs, in
inches, in a city is 3.7 inches. If we want to be 95% confident
that the sample mean is within 2 inches of the true population
mean, what is the minimum sample size that can be taken?
z0.101.282z0.051.645z0.0251.960z0.012.326z0.0052.576 Use the table
above for the z-score, and be sure to round up to the nearest
integer

The lengths of text messages are normally distributed with a
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confidence interval for the population mean. Round your answers to
two decimal places.
z0.10
z0.05
z0.04
z0.025
z0.01
z0.005
1.282
1.645
1.751
1.960
2.326
2.576

The lengths of text messages are normally distributed with a
population standard deviation of 3 characters and an unknown
population mean. If a random sample of 26 text messages is taken
and results in a sample mean of 29 characters, find a 98%
confidence interval for the population mean. Round your answers to
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1.645 1.751 1.960 2.326 2.576 You may use a calculator or the
common z-values above. Select the...

The lengths of text messages are normally distributed with a
population standard deviation of 3 characters and an unknown
population mean. If a random sample of 29 text messages is taken
and results in a sample mean of 30characters, find a 92% confidence
interval for the population mean. Round your answers to two decimal
places
z0.10
z0.05
z0.04
z0.025
z0.01
z0.005
1.282
1.645
1.751
1.960
2.326
2.576
select the correct answer below:
(28.56,31.44)
(29.29,30.71)
(29.08,30.92)
(28.70,31.30)
(29.02,30.98)
(28.91,31.09)

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Your answers can be rounded to three decimal digit accuracy when
entered.

In a random sample of 150 packages shipped by air freight, 26
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Construct a 99% confidence interval for the true proportion
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formula.
zα
1.282
1.645
1.960
2.326
2.576
3.090
α(tail area)
0.1
0.05
0.025
0.01
0.005
0.001
%ile
90
95
97.5
99
99.5
99.9
Your answers can be rounded to three decimal digit accuracy when
entered.
Lower limit is =
Upper limit is =

On the basis of extensive tests, the yield point of a particular
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believed to have affected the normality or the standard
deviation.
Assuming this to be the case, if a sample of 24 modified
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construct a...

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