Basic Statistics > A-Level Question Paper > introduction to statistics unit 5 milestone 5 (All)

introduction to statistics unit 5 milestone 5

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Adam tabulated the values for the average speed on each day of his road trip as 60.5, 63.2, 54.7, 51.6, 72.3, 70.7, 67.2, and 65.4 mph. If Adam wanted to construct a one-sample t-statistic, what would the value for the degrees of freedom be? 4 7 9 8 RATIONALE The degrees of freedom for a 1 sample t-test are df=n-1 where n is the sample size. In this case, n=8, then df = n-1 = 8-1 = 7. CONCEPT T-Tests 2 9/18/2020 Sophia :: Welcome https://strayer.sophia.org/spcc/introduction-to-statistics-2/milestone_take_feedbacks/6219912 2/22 Steven measures the weight of a random sample of 49 basset hounds. The mean weight was 45.8 pounds, with a standard deviation of 3 pounds. Using the alternative hypothesis that μ < 45.8, Steven found a z test statistic of -1.5. What is the p-value of the test statistic? Answer choices are rounded to the thousandths place. 0.067 0.147 0.134 0.055 9/18/2020 Sophia :: Welcome https://strayer.sophia.org/spcc/introduction-to-statistics-2/milestone_take_feedbacks/6219912 3/22 RATIONALE If we go to the chart and the row for the z-column for -1.5 and then the column 0, this value corresponds to 0.0668 or 0.067. CONCEPT How to Find a P-Value from a Z-Test Statistic 3 Sukie interviewed 125 employees at her company and discovered that 21 of them planned to take an extended vacation next year. What is the standard error of the sample proportion? Answer choices are rounded to the thousandths place. 0.080 0.015 0.532 0.033 RATIONALE We can note the SE of the proportion is square root of fraction numerator p with hat on top q with hat on top over denominator n end fraction end root . If we note that , which means . So if we take all this information we can note SE = . CONCEPT Calculating Standard Error of a Sample Proportion 4 9/18/2020 Sophia :: Welcome https://strayer.sophia.org/spcc/introduction-to-statistics-2/milestone_take_feedbacks/6219912 4/22 For a left-tailed test, the critical value of z so that a hypothesis test would reject the null hypothesis at 10% significance level would be __________. Answer choices are rounded to the hundredths place. -1.03 -1.65 -2.33 -1.28 RATIONALE Recall that when a test statistic is smaller than in a left tailed test we would reject Ho. If we go to the standard normal chart and use 10% or 0.10, we will search for the closest value to 10% as closely as possible. 0.1003 corresponds with a z-score of -1.28. CONCEPT How to Find a Critical Z Value 5 Edwin conducted a survey to find the percentage of people in an area who smoked regularly. He defined the label “smoking regularly” for males smoking 30 or more cigarettes in a day and for females smoking 20 or more. Out of 635 people who took part in the survey, 71 are labeled as people who smoke regularly. Edwin wishes to construct a significance test for his data. He finds that the proportion of chain smokers nationally is 14.1%. What is the z-statistic for this data? Answer choices are rounded to the hundredths place. -2.34

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