7) A retired statistics professor has recorded final exam results for decades. The mean final exam score for the population of her students is 82.4 with a standard deviation of 6.5 . In the last year, her standard deviation seems to have changed. She bases this on a random sample of 25 students whose final exam scores had a mean of 80 with a standard deviation of 4.2 . Test the professor's claim that the current standard deviation is different from 6.5 . Use α = .05 .
Express the claim in symbolic form.
Group of answer choices
σ ≠ 6.5
σ ≥ 6.5
σ = 6.5
σ ≤ 6.5
σ > 6.5
σ < 6.5
28) A retired statistics professor has recorded final exam results for decades. The mean final exam score for the population of her students is 82.4 with a standard deviation of 6.5 . In the last year, her standard deviation seems to have changed. She bases this on a random sample of 25 students whose final exam scores had a mean of 80 with a standard deviation of 4.2 . Test the professor's claim that the current standard deviation is different from 6.5 . Use α = .05 .
What is the alternative hypothesis, H1?
Group of answer choices
σ ≥ 6.5
σ < 6.5
σ = 6.5
σ ≤ 6.5
σ ≠ 6.5
σ > 6.5
29) A retired statistics professor has recorded final exam results for decades. The mean final exam score for the population of her students is 82.4 with a standard deviation of 6.5 . In the last year, her standard deviation seems to have changed. She bases this on a random sample of 25 students whose final exam scores had a mean of 80 with a standard deviation of 4.2 . Test the professor's claim that the current standard deviation is different from 6.5 . Use α = .05 .
Find the critical value(s). (Round to the nearest thousandth. If more than one value is found, enter the smallest critical value.)
30) A retired statistics professor has recorded final exam results for decades. The mean final exam score for the population of her students is 82.4 with a standard deviation of 6.5 . In the last year, her standard deviation seems to have changed. She bases this on a random sample of 25 students whose final exam scores had a mean of 80 with a standard deviation of 4.2 . Test the professor's claim that the current standard deviation is different from 6.5 . Use α = .05 .
Find the value of the test statistic. (Round to the nearest ten-thousandth.)
31) A retired statistics professor has recorded final exam results for decades. The mean final exam score for the population of her students is 82.4 with a standard deviation of 6.5 . In the last year, her standard deviation seems to have changed. She bases this on a random sample of 25 students whose final exam scores had a mean of 80 with a standard deviation of 4.2 . Test the professor's claim that the current standard deviation is different from 6.5 . Use α = .05 .
What is the statistical conclusion?
Group of answer choices
32) A retired statistics professor has recorded final exam results for decades. The mean final exam score for the population of her students is 82.4 with a standard deviation of 6.5 . In the last year, her standard deviation seems to have changed. She bases this on a random sample of 25 students whose final exam scores had a mean of 80 with a standard deviation of 4.2 . Test the professor's claim that the current standard deviation is different from 6.5 . Use α = .05 .
State the conclusion in words.
Group of answer choices
a) There is not sufficient evidence to warrant rejection of the claim that the current standard deviation is different from 6.5 .
b) The sample data support the claim that the current standard deviation is different from 6.5 .
c) There is not sufficient sample evidence to support the claim that the current standard deviation is different from 6.5 .
d) There is sufficient evidence to warrant rejection of the claim that the current standard deviation is different from 6.5 .
33) A retired statistics professor has recorded final exam results for decades. The mean final exam score for the population of her students is 82.4 with a standard deviation of 6.5 . In the last year, her mean seems to have changed. She bases this on a random sample of 25 students whose final exam scores had a mean of 80 with a standard deviation of 4.2 . Test the professor's claim that the current mean is different from 82.4 . Use α = .05 .
Express the claim in symbolic form.
Group of answer choices
μ < 82.4
μ > 82.4
μ = 82.4
μ ≠ 82.4
μ ≤ 82.4
μ ≥ 82.4
34) A retired statistics professor has recorded final exam results for decades. The mean final exam score for the population of her students is 82.4 with a standard deviation of 6.5 . In the last year, her mean seems to have changed. She bases this on a random sample of 25 students whose final exam scores had a mean of 80 with a standard deviation of 4.2 . Test the professor's claim that the current mean is different from 82.4 . Use α = .05 .
What is the alternative hypothesis, H1?
Group of answer choices
μ ≤ 82.4
μ ≠ 82.4
μ > 82.4
μ ≥ 82.4
μ < 82.4
μ = 82.4
35) A retired statistics professor has recorded final exam results for decades. The mean final exam score for the population of her students is 82.4 with a standard deviation of 6.5 . In the last year, her mean seems to have changed. She bases this on a random sample of 25 students whose final exam scores had a mean of 80 with a standard deviation of 4.2 . Test the professor's claim that the current mean is different from 82.4 . Use α = .05 .
Find the critical value(s). (Round to the nearest hundredth. If more than one value is found, enter the smallest critical value.)
36) A retired statistics professor has recorded final exam results for decades. The mean final exam score for the population of her students is 82.4 with a standard deviation of 6.5 . In the last year, her mean seems to have changed. She bases this on a random sample of 25 students whose final exam scores had a mean of 80 with a standard deviation of 4.2 . Test the professor's claim that the current mean is different from 82.4 . Use α = .05 .
Find the value of the test statistic. (Round to the nearest thousandth.)
37) A retired statistics professor has recorded final exam results for decades. The mean final exam score for the population of her students is 82.4 with a standard deviation of 6.5 . In the last year, her mean seems to have changed. She bases this on a random sample of 25 students whose final exam scores had a mean of 80 with a standard deviation of 4.2 . Test the professor's claim that the current mean is different from 82.4 . Use α = .05 .
What is the statistical conclusion?
Group of answer choices
38) A retired statistics professor has recorded final exam results for decades. The mean final exam score for the population of her students is 82.4 with a standard deviation of 6.5 . In the last year, her mean seems to have changed. She bases this on a random sample of 25 students whose final exam scores had a mean of 80 with a standard deviation of 4.2 . Test the professor's claim that the current mean is different from 82.4 . Use α = .05 .
State the conclusion in words.
Group of answer choices
27)
Below are the null and alternative Hypothesis,
Null Hypothesis, H0: σ = 6.5
28)
Alternative Hypothesis, Ha: σ > 6.5
29)
Critical value of Χ^2 are 12.40 and 39.36
30)
Test statistic,
Χ^2 = (n-1)*s^2/σ^2
Χ^2 = (25 - 1)*4.2^2/6.5^2
Χ^2 = 10.0204
31)
reject the null hypothesis.
32)
d) There is sufficient evidence to warrant rejection of the claim that the current standard deviation is different from 6.5
33)
Null Hypothesis: μ = 82.4
34)
Alternative Hypothesis: μ ≠ 82.4
35)
Critical value of z are -1.96 and 1.96.
36)
Test statistic,
z = (xbar - mu)/(sigma/sqrt(n))
z = (80 - 82.4)/(6.5/sqrt(25))
z = -1.846
37)
fail to reject null hypothesis.
38)
There is not sufficient evidence to warrant rejection of the claim
that the current mean is different from 82.4 .
7) A retired statistics professor has recorded final exam results for decades. The mean final exam...
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