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a retired statistic professor has recorded final exam results for decades. the mean final exam score for the population of a student is 82.4 with a standard deviation of 6.5. in the last year for standard deviation seems to have changed she bases this on a random sample of 25 students whose final exam had a mean a 80 with a standard deviation of 4.2 test the professor's claim that the current mean is different from 82.4. use a equals 0.05 Assume that o is known to be 6.5
Express the claim in symbolic form. Express the claim in symbolic form. Group of answer choices A )σ > 6.5 B) σ = 6.5 C) σ < 6.5 D) σ ≠ 6.5 E) σ ≥ 6.5 F) σ ≤ 6.5 28) What is the alternative hypothesis, H1? Group of answer choices A) σ < 6.5 B) σ ≤ 6.5 C) σ ≠ 6.5 D) σ = 6.5 E) σ > 6.5 F) σ ≥ 6.5 29) Find the critical value(s). (Round to the nearest thousandth. If more than one value is found, enter the smallest critical value.) 30) Find the value of the test statistic. (Round to the nearest ten-thousandth.) 31) What is the statistical conclusion? Group of answer choices A)Fail to reject H0 B) Reject H0 32) State the conclusion in words. Group of answer choices A) There is not sufficient sample evidence to support 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 evidence to warrant rejection of 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 .

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Varshamittal029idn

The value of the standard deviation does not change and remains the same.

Given, a retired statistic professor has recorded final exam results for decades. the mean final exam score for the population of a student is 82.4 with a standard deviation of 6.5.

The mean μ = 82.4

The standard deviation σ = √[ ((x - μ)2 + (y - μ)2 + (z - μ)2)/3 ]

we have to find the variance,

We now add a constant k to each data value and calculate the new mean μ'.

μ' = ((x + k) + (y + k) + (z + k)) / 3 = (x + y + z) / 3 + 3k/3 = μ + k

We now calculate the new mean standard deviation σ'.

σ' = √[ ((x + k - μ')2 +(y + k - μ')2+(z + k - μ')2)/3 ]

Note that x + k - μ' = x + k - μ - k = x - μ

also y + k - μ' = y + k - μ - k = y - μ and z + k - μ' = z + k - μ - k = z - μ

Therefore σ' = √[ ((x - μ)2 +(y - μ)2+(z - μ)2)/3 ] = σ

If we add the same constant k to all data values included in a data set, we obtain a new data set whose mean is the mean of the original data set PLUS k. The standard deviation does not change.

Hence, the standard deviation does not change.

Learn more about Standard Deviation and Mean here https://brainly.com/question/26941429

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