Question

For the population of infants subjected to fetal surgery for congenital anomalies, the distribution of gestational...

For the population of infants subjected to fetal surgery for congenital anomalies, the distribution of gestational ages at birth is approximately normal with unknown mean μ and standard deviation σ. A random sample of 16 such infants has mean gestational age x̅ = 32.9 weeks and standard deviation s = 4.5 weeks.

  1. Construct a 95% confidence interval for the true population mean μ.
  2. What is the length of this interval?
  3. How large a sample would be required for the 95% confidence interval to have length 3 weeks? Assume that the population standard deviation σ = 4.5 weeks.
  4. How large a sample would be needed for the 95% confidence interval to have length 2 weeks? Assume that the population standard deviation σ = 4.5 weeks.

Homework Answers

Know the answer?
Your Answer:

Post as a guest

Your Name:

What's your source?

Earn Coins

Coins can be redeemed for fabulous gifts.

Not the answer you're looking for?
Ask your own homework help question
Similar Questions
The 95% confidence interval for all the mean weight of infants born to mothers who smoke...
The 95% confidence interval for all the mean weight of infants born to mothers who smoke is µ = 5.40 to 6.80 pounds. The mean weight for a random sample of 25 newborns in this region is 7.2 pounds with a standard deviation (s) of 0.85 pounds. Is the birth weight of the infants in this sample significantly different from that of the general population at α=0.05? (10 points) Explain your response (4 pts). Please show work . Thank you...
An SRS of 18 recent birth records at the local hospital was selected.   In the sample,...
An SRS of 18 recent birth records at the local hospital was selected.   In the sample, the average birth weight was 119.6 ounces and the standard deviation was 6.5 ounces. Assume that in the population of all babies born in this hospital, the birth weights follow a Normal distribution, with unknown mean μ and unknown standard deviation σ . We want to estimate μ based on our sample. A 95% confidence interval for the population mean birth weight based on...
A random sample of 24 recent birth records at the local hospital was selected. In the...
A random sample of 24 recent birth records at the local hospital was selected. In the sample, the average birth weight was 119.6 ounces. Population standard deviation was 6.7 ounces. Assume that in the population of all babies born in this hospital, the birth weights follow a Normal distribution, with mean μ. A 95% confidence interval for the population mean birth weight based on these data is
In a study of the lifespans of mattresses, a random sample of 63 mattresses were subjected...
In a study of the lifespans of mattresses, a random sample of 63 mattresses were subjected to daily use. For this sample, they found that the average time (in months) before the mattress needed replacement was 16.3, and the standard deviation was 1.3. What is the upper confidence limit for a 95% confidence interval for ?μ, the mean time before mattresses need replacement?
A random sample of 125 items is drawn from a population whose standard deviation is known...
A random sample of 125 items is drawn from a population whose standard deviation is known to be σ = 30. The sample mean is  x¯ = 860. (a) Construct an interval estimate for μ with 95 percent confidence. (Round your answers to 1 decimal place.)   The 95% confidence interval is from _________ to __________ (b) Construct an interval estimate for μ with 95 percent confidence, assuming that σ = 60. (Round your answers to 1 decimal place.)   The 95% confidence...
1. For a standard normal distribution, given: P(z < c) = 0.9353 Find c. 2. A...
1. For a standard normal distribution, given: P(z < c) = 0.9353 Find c. 2. A population of values has a normal distribution with μ=195.6μ=195.6 and σ=42.9σ=42.9. You intend to draw a random sample of size n=203n=203. What is the mean of the distribution of sample means? μ¯x=μx¯= What is the standard deviation of the distribution of sample means? (Report answer accurate to 2 decimal places.) σ¯x=σx¯= 3.A population of values has a normal distribution with μ=5.8μ=5.8 and σ=80σ=80. You...
Use the t-distribution to find a confidence interval for a mean μ given the relevant sample...
Use the t-distribution to find a confidence interval for a mean μ given the relevant sample results. Give the best point estimate for μ, the margin of error, and the confidence interval. Assume the results come from a random sample from a population that is approximately normally distributed. A 95% confidence interval for μ using the sample results x̅=10.4, s=5.3, and n=30. Round your answer for the point estimate to one decimal place, and your answers for the margin of...
A random sample of 40 students has a mean annual earnings of $3120. Assume the population...
A random sample of 40 students has a mean annual earnings of $3120. Assume the population standard deviation is $677. Construct a 95% confidence interval for the population mean, μ
Construct a 95% confidence interval for the population standard deviation σ of a random sample of...
Construct a 95% confidence interval for the population standard deviation σ of a random sample of 15 men who have a mean weight of 165.2 pounds with a standard deviation of 12.6 pounds. Assume the population is normally distributed.
1. A sample of 35 circuits from a large normal population has a mean resistance of...
1. A sample of 35 circuits from a large normal population has a mean resistance of 2.35 ohms. We know from past testing that the a) population standard deviation is 0.45 ohms. b) population standard deviation is 0.48 ohms. c) population standard deviation is 0.43 ohms. d) population standard deviation is 0.46 ohms. Determine a 95% confidence interval for the true mean resistance of the population 2. a)Arandomsampleofn=20has x=45ands=8. b)Arandomsampleofn=22has x=48ands=9. c)Arandomsampleofn=20has x=45ands=8. d)Arandomsampleofn=22has x=48ands=9. Form a 95% confidence interval...
ADVERTISEMENT
Need Online Homework Help?

Get Answers For Free
Most questions answered within 1 hours.

Ask a Question
ADVERTISEMENT