Suppose you have selected a random sample of n=9 measurements from a normal distribution. Compare the standard normal zz= values with the corresponding t values if you were forming the following confidence intervals.
(a) 98% confidence interval
z=
t=
(b) 95% confidence interval
z=
t=
(c) 99% confidence interval
z=
t=
a)
98% confidence interval :
z value =2.326 (from excel function: normsinv(0.99))
t =2.896 (from excel function :tinv(0.02,8))
b)
95% confidence interval :
z value =1.96 (from excel function: normsinv(0.975))
t =2.306 (from excel function :tinv(0.05,8))
c)
99% confidence interval :
z value =2.576 (from excel function: normsinv(0.995))
t =3.355 (from excel function :tinv(0.01,8))
Suppose you have selected a random sample of n=9 measurements from a normal distribution. Compare the...
(6 pts) Suppose you have selected a random sample of n 7 measurements from a normal distribution. Compare the standard normal z values with the corresponding t values if you were forming the following confidence intervals. (a) 80% confidence interval (b) 90% confidence interval (c) 95% confidence interval
Assume a random sample of n = 5 measurements from a normal distribution. Compare the standard normal z-values with the corresponding t-values if you were forming a 99% confidence interval.
2. 22 random samples were selected from a population that has a normal distribution. The sample (1 point) has a mean of 99 and a standard deviation of 5 . Construct a 95% confidence interval for the population standard deviation 76 < σ < 141 3.What are the critical values 2? and 2 that correspond to a 99% confidence level and a (lpom) sample size of 30? 13.121, 52.336 13.787, 53.672 14.257, 49.588 19.768, 39.087
The random sample shown below was selected from a normal distribution 7, 3, 9, 8, 3,6 Complete parts a and b. a. Construct a 95% confidence interval for the population mean μ (Round to two decimal places as needed.) b. Assume that sample mean x and sample standard deviation s remain exactly the same as those you just calculated but that are based on a sample of n -25 observations. Repeat part a. What is the effect of increasing the...
Suppose that X . . . . . Xn is a random sample from a normal population with unknown mean μ x and unknown variance σ I. What is the form of a 95% confidence interval for μχ . Îs your interval the shortest 95% confidence interval for μχ that is avail- able? 2. What is the form of a 95% confidence interval for . Is your interval the shortest 95% confidence interval for σ,' that is avail- able? 3....
The random sample shown below was selected from a normal distribution. 3,6,8,3,8,8 Complete parts a and b. a. Construct a 99% confidence interval for the population mean μ. (1.971,10.03) (Round to two decimal places as needed.) b. Assume that sample mean x overbar x and sample standard deviation s remain exactly the same as those you just calculated but that are based on a sample of n=25 observations. Repeat part a. What is the effect of increasing the sample size...
The random sample shown below was selected from a normal distribution. 3,6,8,3,8,8 Complete parts a and b. a. Construct a 99% confidence interval for the population mean μ. (1.97,10.03) (Round to two decimal places as needed.)b. Assume that sample mean x overbar x and sample standard deviation s remain exactly the same as those you just calculated but that are based on a sample of n=25 observations. Repeat part a. What is the effect of increasing the sample size on...
and for 2. A random sample of n measurements is selected from a population with unknown mean known standard deviation o = 10. Calculate the width of a 95% confidence interval for these values of n: a. n=100 b. n=200 c. n=400 d. n=1000 e. n=2000
7.5 Suppose you draw a random sample of size n from a normal distribution with unknown mean u and known standard deviation o and construct a 95% confidence interval for u. If you want to halve the margin of error, how much larger would the sample size have to be?
Identify the critical t. An independent random sample is selected from an approximately normal population with unknown standard deviation. Find the degrees of freedom and the critical t value t∗t∗ for the given sample size and confidence level. Round critical t values to 4 decimal places. Sample size, n Confidence level Degree of Freedom Critical value, t∗t∗ 22 90 11 95 3 98 20 99