Question

A clinical trial was conducted to test the effectiveness of a drug used for treating insomnia in older subjects. After treatment with the drug, 27 subjects had a mean wake time of 96.7 min and a standard deviation of 41.8 min. Assume that the 27 sample values appear to be from a normally distributed population and construct a 90% confidence interval estimate of the standard deviation of the wake times for a population with the drug treatments. Does the result indicate whether the treatment is effective?

Find the confidence interval estimate. _ min < sigma < _ min

My main issues are finding the right-tailed and left-tailed critical values.

Answer #1

A clinical trial was conducted to test the effectiveness of a
drug used for treating insomnia in older subjects. After treatment
with the drug, 22 subjects had a mean wake time of
97.7 min and a standard deviation of 40.4 min. Assume that the
22 sample values appear to be from a normally distributed
population and construct a 95% confidence interval estimate of the
standard deviation of the wake times for a population with the drug
treatments. Does the result...

A clinical trial was conducted to test the effectiveness of a
drug used for treating insomnia in older subjects. After treatment
with the drug, 22 subjects had a mean wake time of 93.8 min and a
standard deviation of 44.1 min. Assume that the 22 sample values
appear to be from a normally distributed population and construct a
95% confidence interval estimate of the standard deviation of the
wake times for a population with the drug treatments. Does the
result...

A clinical trial was conducted to test the effectiveness of a
drug used for treating insomnia in older subjects. After treatment
with the drug, 24 subjects had a mean wake time of 90.8 min and a
standard deviation of 43.4 min. Assume that the 24 sample values
appear to be from a normally distributed population and construct a
95 % confidence interval estimate of the standard deviation of the
wake times for a population with the drug treatments. Does the...

A clinical trial was conducted to test the effectiveness of a
drug used for treating insomnia in older subjects. After treatment
with the drug, 15 subjects had a mean wake time of 90.6 min and a
standard deviation of 43.4 min. Assume that the 15 sample values
appear to be from a normally distributed population and construct a
90% confidence interval estimate of the standard deviation of the
wake times for a population with the drug treatments. Does the
result...

A clinical trial was conducted to test the effectiveness of a
drug used for treating insomnia in older subjects. After treatment
with the drug,1515subjects had a mean wake time of 95.195.1 min
and a standard deviation of 41.541.5 min. Assume that the 1515
sample values appear to be from a normally distributed population
and construct a 9898% confidence interval estimate of the standard
deviation of the wake times for a population with the drug
treatments. Does the result indicate whether...

A clinical trial was conducted to test the effectiveness of a
drug for treating insomnia in older subjects. Before treatment, 21
subjects had a mean wake time of 105.0 min. After treatment, the
21 subjects had a mean wake time of 84.6 min and a standard
deviation of 22.6 min. Assume that the 21 sample values appear to
be from a normally distributed population and construct a 95%
confidence interval estimate of the mean wake time for a population
with...

A clinical trial was conducted to test the effectiveness of a
drug for treating insomnia in older subjects. Before
treatment,
25
subjects had a mean wake time of
103.0
min. After treatment, the
25
subjects had a mean wake time of
75.9
min and a standard deviation of
24.8
min. Assume that the
25
sample values appear to be from a normally distributed
population and construct a
99%
confidence interval estimate of the mean wake time for a
population with...

A clinical trial was conducted to test the effectiveness of a
drug for treating insomnia in older subjects. Before treatment,
14
subjects had a mean wake time of 102.0 min. After treatment,
the 14 subjects had a mean wake time of
97.4 min and a standard deviation of 23.2 min. Assume that the
14 sample values appear to be from a normally distributed
population and construct a
90% confidence interval estimate of the mean wake time for a
population with...

A clinical trial was conducted to test the effectiveness of a
drug for treating insomnia in older subjects. Before treatment, 19
subjects had a mean wake time of 103.0 min. After treatment, the
19 subjects had a mean wake time of 94.8 min and a standard
deviation of 24.9 min. Assume that the 19 sample values appear to
be from a normally distributed population and construct a 99%
confidence interval estimate of the mean wake time for a population
with...

A
clinical trial was conducted to test the effectiveness of a drug
for treating insomnia in older subjects. Before treatment, 25
subjects had a mean wake time of 103.0 min. After treatment, the 25
subjects had a mean wake time of 96.1 min and a standard deviation
of 22.8 min. Assume thay the 25 sample values appear to be from a
normally distrubuted population and construct a 95% confidence
interval estimate of the mean wake time for a population with...

ADVERTISEMENT

Get Answers For Free

Most questions answered within 1 hours.

ADVERTISEMENT

asked 3 minutes ago

asked 6 minutes ago

asked 11 minutes ago

asked 13 minutes ago

asked 23 minutes ago

asked 24 minutes ago

asked 28 minutes ago

asked 42 minutes ago

asked 54 minutes ago

asked 54 minutes ago

asked 55 minutes ago

asked 1 hour ago