Consider the following point estimators, W, X, Y, and Z of
μ: W = (x1 +
x2)/2;
X = (2x1 + x2)/3; Y =
(x1 + 3x2)/4; and Z =
(2x1 + 3x2)/5. Assuming
that x1 and x2 have both been drawn independently from a population
with mean μ and variance σ2
then which of the following is true...Which of the following point
estimators is the most efficient?
An estimator is unbiased if the mean of its sampling distribution is the population parameter being estimated.
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A professor found that historically, the scores on the final exam tend to follow a normal distribution. A random sample of nine test scores from the current class had a mean score of 187.9 points and a sample standard deviation of 32.4 points. Find the 90% confidence interval for the population mean score of the current class.
A taxi company is interested in the amount of time its vehicles
are out of operation for repair. Find a 90% confidence interval for
the mean number of days in a month that all taxis are out of
operation for repair. A random sample of nine taxis had the
following number of days that each was in repair (Note that we are
using sample data and must estimate the sample standard deviation
using the sample formula.):
10 16 19 14 19 21 22 8 17
A. 13.09 up to 19.35
B. 12.54 up to 19.9
C. 13.25 up to 19.19
D. 12.24 up to 20.2
Test Ho: µ =100; H1: µ < 100, using n = 36 and alpha = .05 If the sample mean = 95 and the sample standard deviation = 10, which of the following is true?
A. test statistic = -3.00; critical value = -1.69; we fail to reject Ho.
B. test statistic = -3.00; critical value = -1.69; we reject Ho and accept H1.
C. test statistic = 3.00; critical value = 1.69; we reject Ho.
D. None of these answers are correct.
Test Ho: µ =100; H1: µ < 100, using n = 36 and alpha = .05 If the sample mean = 95 and the sample standard deviation = 10, which of the following is true?
A. test statistic = -3.00; critical value = -1.69; we fail to reject Ho.
B. test statistic = -3.00; critical value = -1.69; we reject Ho and accept H1.
C. test statistic = 3.00; critical value = 1.69; we reject Ho.
D. None of these answers are correct.
Consider the following point estimators, W, X, Y, and Z of μ: W = (x1 +...
Consider the following point estimators, W, X, Y, and Z of μ: W = (x1 + x2)/2; X = (2x1 + x2)/3; Y = (x1 + 3x2)/4; and Z = (2x1 + 3x2)/5. Assuming that x1 and x2 have both been drawn independently from a population with mean μ and variance σ2 then which of the following is true... Which of the following point estimators is the most efficient? A. X B. W C. Y D. Z
Test Ho: µ =100; H1: µ < 100, using n = 36 and alpha = .05 If the sample mean=92 and the sample standard deviation = 18, which of the following is true? A. test statistic = -2.67; critical value = 1.69; we fail to reject Ho. B. test statistic = -2.67; critical value = 1.96; we fail to reject Ho. C. test statistic = -2.67; critical value = -1.96; we reject Ho. D. test statistic = -2.67; critical value...
Assume that you have a sample of n 1-7, with the sample mean X1-43, and a sample standard deviation of S1-4, and you have an independent sample of n2-13 from another population with a sample mean of x2 39 and the sample standard deviation S2-7. Complete parts (a) through (d). Click here for page 1 of critical values oft. Click here for page 2 of critical values of t. a. What is the value of the pooled-variance ISTAT test statistic...
2. Assume that you have a sample of n = 8 with the sample mean X1 = 42 and a sample standard deviation Si = 4, and you have an independent sample of n2 = 15 from another population with a sample mean of X2 = 34 and a sample standard deviation S2 = 5. a. What is the value of the pooled-variance tsTAT test statistic for testing Ho H1 = H2? b. In finding the critical value, how many...
Please clearly show and label each step Consider the following hypothesis test: Ho: μ = 16 H1: μ ≠ 16 A sample of 50 provided a sample mean of 15.15. The population standard deviation is 3. Compute the value of the test statistic. What is the p value? At α = 0.05, what is the rejection rule using the critical value? What is your conclusion?
Please label and show each step 2. Consider the following hypothesis test: Ho: μ ≤ 50 H1: μ > 50 A sample of 60 is used and the population standard deviation is 8. Use α=0.05. a. Z critical = _______________ b. Sample mean = 53.5, z calc = ______________. Do you reject Ho? c. Sample mean = 51.8, z calc = ______________. Do you reject Ho? d. The Pvalue for c is:_________________
Consider the following hypothesis statement using α= 0.10 and the following data from two independent samples. Complete parts a and b below. X1 = 66 Ho P1-p2 20 x2 = 70 n2 = 130 H: P-P20 n1 = 125 Click here to view page 1 of the standard normal table Click here to view page 2 of the standard normal table. a. Calculate the appropriate test statistic and interpret the result. What is the test statistic? (Round to two decimal...
You wish to test the following claim (H1) at a significance level of α=0.10α=0.10. Ho:μ=58.6 H1:μ>58.6 You believe the population is normally distributed, but you do not know the standard deviation. You obtain the following sample of data: data 66.8 39.2 64.7 58.9 56 58.4 66.6 57.4 53.6 60.6 41.8 66 What is the critical value for this test? (Report answer accurate to three decimal places.) critical value = What is the test statistic for this sample? (Report answer accurate...
You wish to test the following claim (H1H1) at a significance level of α=0.10α=0.10. Ho:μ=81.4Ho:μ=81.4 H1:μ≠81.4H1:μ≠81.4 You believe the population is normally distributed, but you do not know the standard deviation. You obtain the following sample of data: data 83.3 77.1 85.9 86.3 77.6 79 88.4 81.3 89 What is the critical value for this test? (Report answer accurate to three decimal places.) critical value = ±± What is the test statistic for this sample? (Report answer accurate to three...
Random samples of two species of iris gave the following petal lengths (in cm). x1, Iris virginica 5.1 5.9 4.5 4.9 5.7 4.8 5.8 6.4 5.7 5.9 x2, Iris versicolor 4.5 4.3 4.7 5.0 3.8 5.1 4.4 4.2 (a) Use a 5% level of significance to test the claim that the population standard deviation of x1 is larger than 0.55. What is the level of significance? State the null and alternate hypotheses. H0: σ = 0.55; H1: σ > 0.55...