Question

1. Identify whether each of the situations below is a one-tailed or two-tailed test. Next identify the dependent variable. Then write the research and null hypothesis in symbols (i.e. H1: µ_{. . .} =/> etc . . .). You should clearly identify the two groups using subscripts after each µ.
   1. You are interested in finding out whether the average household income of Washington residents is different from the national average for households in other states.
   2. You hypothesize that students at liberal arts colleges attend more parties per month than students in state universities.
   3. An economist believes that the average income of elderly women is smaller than the average income of elderly men.
   4. Is there a difference in the amount of time students living on campus and students living off campus devote to studying each week?
   5. Math scores for a group of third graders enrolled in an accelerated math program are predicted to be higher than the scores for non-enrolled third graders.
   6. The number of times someone gets sick each year is predicted to be lower for adults who own dogs than for non-dog owners.

Answer 1

ANSWER:

Given that,

a)

Test type: two-sided [indication: .... of Washington residents is different from ……]

Dependent Variable: household income

Hypotheses:

Null, H₀: µ₁ = µ₂ [µ₁ = average household income of Washington residents, µ₂ =the national average income for households in other states]

Alternative, H_A: µ₁ ≠ µ₂

Ans: 1 to 3

b)

Test type: one-sided [indication: .... arts colleges attend more parties per month than ……]

Dependent Variable:Number of parties attended by students

Hypotheses:

Null, H₀: µ₁ = µ₂ [µ₁ = average number of parties attended by arts college students, µ₂ =average number of parties attended by state university students]

Alternative, H₁: µ₁ > µ₂

Ans: 4 to 6

c)

Test type: one-sided [indication: .... of elderly women is smaller than the average income of elderly men…]

Dependent Variable: Income of elderly women and men

Hypotheses:

Null, H₀: µ₁ = µ₂ [µ₁ = average income of elderly women, µ₂ =average income of elderly men]

Alternative, H₁: µ₁ < µ₂

Ans: 7 to 9

d)

Test type: two-sided [indication: Is there a difference ……]

Dependent Variable: amount of time students devote to studying each week

Hypotheses:

Null, H₀: µ₁ = µ₂ [µ₁ = average amount of time on-campus students devote to studying each week,

µ₂ =average amount of time off-campus students devote to studying each week]

Alternative, H₁: µ₁ ≠ µ₂

Ans:10 to 12

e)

Test type: one-sided [indication: .... predicted to be higher than …….]

Dependent Variable: Math scores for a group of third graders

Hypotheses:

Null, H₀: µ₁ = µ₂ [µ₁ = average math score of third graders enrolled in an accelerated math program,

µ₂ =average math scores for non-enrolled third graders]

Alternative, H₁: µ₁ > µ₂

Ans: 13 to 15

f)

Test type: one-sided [indication: .... predicted to be lower than …….]

Dependent Variable: number of times someone gets sick each year

Hypotheses:

Null, H₀: µ₁ = µ₂ [µ₁ = average number of times adults who own dogs get sick each year

µ₂ =average number of times adults who do not own dogs get sick each year]

Alternative, H₁: µ₁ < µ₂

Ans: 16 to 18