Question

According to a famous nutritionist, the standard deviation for number of milligrams of vitamin C per 100 grams of fruits and vegetables is 12.7 mg. A skeptical researcher believed this number was too low and took a same of 23 fruits and vegetables to test the claim. The sample standard deviation for the amount of vitamin C was 16.5 mg. With alpha = 0.05, test the claim.

a) Is this a test that uses, z-scores, t-scores, or chi-squared values?

b)Does this problem involve proportions?

c) What is(are) the critical value(s) for the problem?

d)What is the test value and which formula did you use? The formulas are numbered.

e) Should the researcher reject the claim?

Answer 1

given data are:-

sampel size (n) = 23

sampel sd (s) = 16.5

a).in this test we will use chi squared values.

because this is a test for 1 sample variance (here, sd )

b).no, this problem does not involve proportions.

c).hypothesis:-

the researcher's claim is the alternative hypothesis.

the chi square critical value is:-

d).test statistic be:-

[using chi square table]

e).decision:-

we reject the null hypothesis and conclude that there is sufficient evidence to support the reasercher's claim at 0.05 level of significance.

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