Milestone 5 questions with answers 2022

A researcher has a table of data with four column variables and three row variables. The value for the degrees of freedom in order to calculate the statistic is __________. 12 6 3 11 RATIONALE Recall to get the de ...

A researcher has a table of data with four column variables and three row variables. The value for the degrees of freedom in order to calculate the statistic is __________. 12 6 3 11 RATIONALE Recall to get the degrees of freedom we use df = (r-1)(c-1) where c and r are the number of rows and columns. This means df = (4-1)(3-1) = 3*2 =6. CONCEPT Chi-Square Test for Association and Independence 2 7/2/2020 Sophia :: Welcome https://snhu.sophia.org/spcc/introduction-to-statistics-2/milestone_take_feedbacks/4416387 2/21 What value of z* should be used to construct an 88% confidence interval of a population mean? Answer choices are rounded to the thousandths place. 1.220 1.645 1.555 1.175 RATIONALE Using the z-chart to construct an 88% CI, this means that there is 6% for each tail. The lower tail would be at 0.06 and the upper tail would be at (1 - 0.06) or 0.94. The closest to 0.94 on the z-table is between 0.9394 and 0.9406. 7/2/2020 Sophia :: Welcome https://snhu.sophia.org/spcc/introduction-to-statistics-2/milestone_take_feedbacks/4416387 3/21 0.9394 corresponds with a z-score of 1.55. 0.9406 corresponds with a z-score of 1.56. Taking the average of these two scores, we get a z-score of 1.555. CONCEPT Confidence Intervals 3 A market research company conducted a survey to find the level of affluence in a city. They defined the category "affluence" for males earning $100,000 or more annually and for females earning $80,000 or more annually. Out of 267 persons who replied to their survey, 32 are listed under this category. What is the standard error of the sample proportion? Answer choices are rounded to the hundredths place. 0.32 0.20 1.96 0.02 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 Mike tabulated the following values for heights in inches of seven of his friends: 65, 71, 74, 61, 66, 70, and 72. Mike wishes to construct a 95% confidence interval. 7/2/2020 Sophia :: Welcome https://snhu.sophia.org/spcc/introduction-to-statistics-2/milestone_take_feedbacks/4416387 4/21 What value of t* should Mike use to construct the confidence interval? Answer choices are rounded to the hundredths place. 4.58 2.45 1.94 2.37 7/2/2020 Sophia :: Welcome https://snhu.sophia.org/spcc/introduction-to-statistics-2/milestone_take_feedbacks/4416387 5/21 RATIONALE Recall that we have n = 7, so the df = n-1 = 6. So if we go to the row where df = 7 and then 0.025 for the tail probability, this gives us a value of 2.447 or 2.45. Recall that a 95% confidence interval would have 5% for the tails, so 2.5% for each tail. We can also use the last row and find the corresponding confidence level (see 95%). CONCEPT How to Find a Critical T Value 5 A market research company conducted a survey of two groups of students from different schools. They found that students from school A spent an average of 90 minutes studying daily, while the students from school B spent an average of 75 minutes daily. They want to find out if the difference in the mean times spent studying by the students of the two schools is statistically significant. Which of the following sets shows the correct null hypothesis and alternative hypothesis? Null Hypothesis: The difference in the mean times spent by the schools' students is 15 minutes. Alternative Hypothesis: There is no difference in the mean times spent by the schools' students