Chapter 11.9, Problem 67SE

A school counselor is conducting a research study to examine whether there is a relationship between the number of times teenagers report vaping per week and their academic performance, measured by GPA. The counselor collects data from a sample of high school students. Write the null and alternative hypotheses for this study. Clearly state your hypotheses in terms of the correlation between vaping frequency and academic performance.     EditViewInsertFormatToolsTable 12pt   Paragraph

A smallish urn contains 25 small plastic bunnies – 7 of which are pink and 18 of which are white. 10 bunnies are drawn from the urn at random with replacement, and X is the number of pink bunnies that are drawn. (a) P(X = 5) ≈ (b) P(X<6) ≈ The Whoville small urn contains 100 marbles – 60 blue and 40 orange. The Grinch sneaks in one night and grabs a simple random sample (without replacement) of 15 marbles.  (a) The probability that the Grinch gets exactly 6 blue marbles is         [ Select ]      ["≈ 0.054", "≈ 0.043", "≈ 0.061"]  . (b) The probability that the Grinch gets at least 7 blue marbles is         [ Select ]      ["≈ 0.922", "≈ 0.905", "≈ 0.893"]  . (c) The probability that the Grinch gets between 8 and 12 blue marbles (inclusive) is         [ Select ]      ["≈ 0.801", "≈ 0.760", "≈ 0.786"]  . The Whoville small urn contains 100 marbles – 60 blue and 40 orange. The Grinch sneaks in one night and grabs a simple random sample (without replacement) of 15 marbles.  (a)…

Suppose an experiment was conducted to compare the mileage(km) per litre obtained by competing brands of petrol I,II,III. Three new Mazda, three new Toyota and three new Nissan cars were available for experimentation. During the experiment the cars would operate under same conditions in order to eliminate the effect of external variables on the distance travelled per litre on the assigned brand of petrol. The data is given as below: Brands of Petrol Mazda Toyota Nissan I 10.6 12.0 11.0 II 9.0 15.0 12.0 III 12.0 17.4 13.0 (a) Test at the 5% level of significance whether there are signi cant differences among the brands of fuels and also among the cars. [10] (b) Compute the standard error for comparing any two fuel brands means. Hence compare, at the 5% level of significance, each of fuel brands II, and III with the standard fuel brand I. [10]