Solution:
If a population distribution is known to be normal, then it follows
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N (
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: mean
: Variance
If a population distribution is known to be normal, then it follows that:
Consider a normal population distribution with the value of
known. a) What is the confidence level for the interval (i) x
1.96 n (ii) x 2.65 n (iii) x 3.34 n b) What value of z in
the confidence interval formula x z n x z n 2 2 ,
results in a confidence level of (i) 97.96% (ii) 78.88% (iii)
99.94% c) Would a 90% C.I. be narrower...
For a population that follows a normal distribution, if the z-score of a sample point is above 3, it has a percentile rank greater than 99%. True or False.
. Suppose a random sample of 25 is taken from a population that follows a normal distribution with unknown mean and a known variance of 144. Provide the null and alternative hypotheses necessary to determine if there is evidence that the mean of the population is greater than 100. Using the sample mean, Y, as the test statistic and a rejection region > k}, find the value of k so that α = 0.15. of the form - Using the...
PLEASE SHOW ALL THE WORKING
Consider a normal population distribution with the value of
known. a) What is the confidence level for the interval (i) x
1.96 n (ii) x 2.65 n (iii) x 3.34 n b) What value of z in
the confidence interval formula x z n x z n 2 2 ,
results in a confidence level of (i) 97.96% (ii) 78.88% (iii)
99.94% c) Would...
The height of the galactic population of humans follows a normal distribution with mean µ = 70 inches and standard deviation σ = 2.5 inches. In order to fit in their armor, stormtroopers must be between 72 inches and 74 inches tall. (a) What percentage of the population is eligible to be stormtroopers? (b) Luke is taller than 75% of the population. Find the difference in his height and the height of the shortest acceptable stormtrooper. Is he actually “a...
Consider a normal population distribution with the value of a known. (a) What is the confidence level for the interval 72.850/Vn? (Give answer accurate to 1 decimal place.) % (b) What is the confidence level for the interval 7+20/vi? (Give answer accurate to 1 decimal place.) % (c) What value of 2a/2 in the Cl formula results in a confidence level of 92.4%? (Give answer accurate to 2 decimal places.) (d) Answer the question posed in part (C) for a...
1. A population of values follows a normal distribution with standard deviation 5 and unknown mean. A random sample of size 16 has mean 24. a) Write what each number represents. b) Find and interpret the 95% CI for the unknown population mean. c) Is 30 a plausible population mean? Explain.
A manufacturing process ball bearings with diameters that have a normal distribution with known population standard deviation of .03 centimeters. Ball bearings with diameters that are too small or too large are undesirable. In order to test the claim that μ = 0.50 centimeters, perform a two-tailed hypotheses test at the 5% level of significance. A random sample of 49 gave a mean of 0.48 centimeters. Perform a hypotheses test and state your decision.
3. Suppose that the length of iron rods from a certain factory follows the normal distribution with known standard deviation o = 0.2 m but unknown mean u. Construct a 88% confidence interval for the population mean u if a random sample of n = 16 of these iron rods has sample mean of 6 m. Z= E = CI:
1. The distribution of the weekly incomes of a restaurant manager follows a normal distribution with a mean of $1000 and the standard deviation of $100. Using the concept of area under the normal cure and the z-score table, determine the following: a. What percentage of the managers earn a weekly income between $750 and $1225? Draw a normal curve, and shade the desired area on your diagram. b. What percentage of the managers earn a weekly income between $1100...