Question

The test statistic of a two-tailed t-test for a sample size of 12 was found to be 2.1. At a significance level of α = 0.05 ,which of the following statements is correct?

Group of answer choices

a.The P-value is smaller than 0.05

b.We fail to reject the Null hypothesis

c.The test statistic is in the critical region

d.The alternative hypothesis is H1:

A market researcher wants to estimate the proportion of households in the Bay Area who order food online at least twice a week. At least how many households does she need to survey to obtain an answer with a 3% margin of error (i.e., E = 0.03) at a 90% level of confidence?

Group of answer choices

501

271

752

385

The 90% confidence interval of the proportion of adult residents in a county with at least some college education is 0.48 < p < 0.54.

Indicate which of the following statement(s) is correct:

Group of answer choices

One cannot justify the claim that the majority of the adult residents received at least some college education

The margin of error of this study is 0.06

The significance level (α) of this study is 0.05

There is a 90% chance that p is more than 50%

Answer 1

1).We fail to reject the Null hypothesis (B)

[ explanation:-

df = (n-1) = (12-1) = 11

p value is = 0.0596 [ in any blank cell of excel type =T.DIST.2T(2.1,11) ]

decision:-

p value = 0.0596 > 0.05 (alpha)...we fail to reject the null hypothesis.]

2).given data are:-

the needed sample size be:-

3).One cannot justify the claim that the majority of the adult residents received at least some college education

[ explanation:-

the confidence interval contains the value 0.5..so, we fail to reject the null hypothesis...so, One cannot justify the claim that the majority of the adult residents received at least some college education.

the other options are not true because,

the level of significance = (1-c) = (1-0.90) = 0.10 0.05 ]

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