Listed below are weights(hectograms) of randomly selected girls at birth. Here are the summary statistics: n=12, =...

Listed below are weights(hectograms) of randomly selected girls at birth. Here are the summary statistics: n=12, = 31.167hg, s= 3.157hg. Use the sample data to construct a 95% confidence interval for the mean birth weight of girls.

33, 28, 33, 37, 31, 32, 31, 28, 34, 28, 33, 26

Solutions

Expert Solution

Solution:
Mean ˉx=∑xn

=33+28+33+37+31+32+31+28+34+28+33+26 / 12

=374/12

=31.1667

= 31.17

s = 3.157

n = 12

Degrees of freedom = df = n - 1 = 12 - 1 = 11

At 95% confidence level the t is ,

= 1 - 95% = 1 - 0.95 = 0.05

/ 2 = 0.05 / 2 = 0.025

t /2,df = t0.025,11 =2.201

Margin of error = E = t/2,df * (s / $\sqrt$ n)

= 2.201 * (3.157 / $\sqrt$ 12)

= 2.006

Margin of error =2.006

The 95% confidence interval estimate of the population mean is,

- E < < + E

31.17 - 2.006 < < 31.17 + 2.006

29.164 < < 33.176

(29.164, 33.176 )

orchestra answered 1 year ago

Next > < Previous

Related Solutions

Here are summary statistics for randomly selected weights of newborn? girls: n equals = 229 229?,...

Here are summary statistics for randomly selected weights of newborn? girls: n equals = 229 229?, x overbar x equals = 27.3 27.3 ?hg, s equals = 6.4 6.4 hg. Construct a confidence interval estimate of the mean. Use a 98 98?% confidence level. Are these results very different from the confidence interval 25.8 25.8 hg less than < mu ? less than < 28.6 28.6 hg with only 16 16 sample? values, x overbar x equals = 27.2 27.2...

Here are summary statistics for randomly selected weights of recent girls: n equals 168, x =...

Here are summary statistics for randomly selected weights of recent girls: n equals 168, x = 27.2 hg, s = 7.5 hg. Construct a confidence interval estimate of the mean. Use a 99% confidence level. Are these results very different from the confidence interval 25.4 hg < u < 29.4 hg with only 19 sample values, x= 27.4 hg, and s =n3.1 hg?

Here are summary statistics for randomly selected weights of newborn girls: n =191, x̅ = 33.2...

Here are summary statistics for randomly selected weights of newborn girls: n =191, x̅ = 33.2 hg, s = 6.1 hg. Construct a confidence interval estimate of the mean. Use a 90% confidence level. Are these results very different from the confidence interval 32.9 hg < μ < 34.3 hg with only 19 sample values, x̅ = 33.6 hg, and s = 1.7 hg? A. What is the confidence interval for the population mean μ? ____ hg < μ <...

Here are the summary statistics for randomly selected weights of newborn girls: n=237, mean=33.8 hg, and...

Here are the summary statistics for randomly selected weights of newborn girls: n=237, mean=33.8 hg, and s=6.2 hg. Construct a confidence interval estimate of the mean. Use a 90% confidence level

Here are summary statistics for randomly selected weights of newborn girls: n = 192, X=26.5 hg,...

Here are summary statistics for randomly selected weights of newborn girls: n = 192, X=26.5 hg, S= 7.1 Construct a confidence interval estimate of the mean. Use a 99% confidence level. Are these results very different from the confidence interval 24.4 hg < U < 28.0 hg with only 19 sample values, X= 26.2 hg, and S= 2.7 Hg? What is the confidence interval for the population mean ? ? ___hg < U< ___ hg

Listed below are weights (hectograms or hg) of randomly selected girls at birth. Use the sample...

Listed below are weights (hectograms or hg) of randomly selected girls at birth. Use the sample data to construct a 95% confidence interval for the mean weight of girls. 33 28 33 37 31 32 31 28 43 28 33 26 30 31 28 Address the following questions: What is alpha What is Zα/2 or tα/2 Which formula did you use and what is the Confidence Interval?

Here are summary statistics for randomly selected weights of newborn girls: n=210, x =26.9 hg, s=6.1...

Here are summary statistics for randomly selected weights of newborn girls: n=210, x =26.9 hg, s=6.1 hg. Construct a confidence interval estimate of the mean. Use a 90% confidence level. Are these results very different from the confidence interval 25.8 hg <ul <27.4 hg with only 16 sample values, x =26.6 hg, and s =1.9 hg?

Q7. Here are summary statistics for randomly selected weights of newborn girls: n=210, x overbarx=28.9 hg,...

Q7. Here are summary statistics for randomly selected weights of newborn girls: n=210, x overbarx=28.9 hg, s=6.3hg. Construct a confidence interval estimate of the mean. Use a 99% confidence level. Are these results very different from the confidence interval 27.0 hgless than What is the confidence interval for the population mean muμ? ____hgless than

Here are summary statistics for randomly selected weights of newborn girls: n=187, x =30.8 hg, s=7.9...

Here are summary statistics for randomly selected weights of newborn girls: n=187, x =30.8 hg, s=7.9 hg. Construct a confidence interval estimate of the mean. Use a 90% confidence level. Are these results very different from the confidence interval 29.0 hg-mu-t32.4 hg with only 14 sample values, x=30.7 hg, and s=3.6 hg

Here are summary statistics for randomly selected weights of newborn girls: nequals 219 , x overbar...

Here are summary statistics for randomly selected weights of newborn girls: nequals 219 , x overbar equals29.4 hg, sequals 7.5 hg. Construct a confidence interval estimate of the mean. Use a 99 % confidence level. Are these results very different from the confidence interval 26.9 hgless than muless than30.9 hg with only 20 sample values, x overbar equals28.9 hg, and sequals 3.2 hg? What is the confidence interval for the population mean u? ______hg < u < _____ hg (Round...

Subjects