Question

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A history instructor hypothesizes that the students who earn a C or better spend more time outside of class on the coursework than students who receive a D or an F. She collects the following data (number of hours spent outside of class on the course work) from two samples of students. What does she conclude?

-Do all steps for this problem but DO NOT redo the math provided for you.  

C or better           D or F

8 4 4 2 1 5 2 2 1 3

6 2 1 0 3 2 1 5

Data Box Group 1 Sum of x = 32 Sum of x squared = 144 Squared sum of x = 1024      Variance = 4.16 Mean = 3.2 N = 10

Data Box Group 2 Sum of x= 20 Sum of x squared = 80 Squared sum of x = 400        Variance = 3.75 Mean = 2.5 N = 8

a. What is step 1?

Group of answer choices

H0: μ1 = μ2 & H1: μ1 ≠ μ2

H0: μ1 ≥ μ2 & H1: μ1 < μ2

H0: μ1 ≤ μ2 & H1: μ1 > μ2

b. Set up Step 2

Group of answer choices

alpha

      [ Choose ]            16            directional            .01            1 tail            2.120            18            1.746            .05            non-directional      

tails?

      [ Choose ]            16            directional            .01            1 tail            2.120            18            1.746            .05            non-directional      

Direction?

      [ Choose ]            16            directional            .01            1 tail            2.120            18            1.746            .05            non-directional      

df?

      [ Choose ]            16            directional            .01            1 tail            2.120            18            1.746            .05            non-directional      

Critical value?

      [ Choose ]            16            directional            .01            1 tail            2.120            18            1.746            .05            non-directional      

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Question 123 pts

c, What is step 3?

Group of answer choices

Estimate of the standard error between the sample means

      [ Choose ]            .999            1.746            positive            2.999            negative            .701      

tobt value

      [ Choose ]            .999            1.746            positive            2.999            negative            .701      

Positive or negative tobt

      [ Choose ]            .999            1.746            positive            2.999            negative            .701      

d. Is step 4 to Retain H₀?

Group of answer choices

True

False

e. Set up step 5.

Group of answer choices

It appears that students who earn C or better do not spend significantly more time outside of class doing coursework.

It appears that students who earn C or better spend significantly less time outside of class doing coursework.

It appears that students who earn C or better spend significantly more time outside of class doing coursework.

f. When you reject H₀ for the type of test on question #10 what do you do after step 5, conclusion?

Group of answer choices

Tukey HSD

confidence interval and effect size

nothing

Answer 1

a)

H0: μ1 ≤ μ2 & H1: μ1 > μ2

2)

α=0.05

Degree of freedom, DF=   n1+n2-2 =    16
t-critical value , t* =        1.746
one tail test , directional

3)

pooled std dev , Sp=   √([(n1 - 1)s1² + (n2 - 1)s2²]/(n1+n2-2)) =    1.6334
std error , SE =    Sp*√(1/n1+1/n2) =    0.7748

4) TRUE

5) It appears that students who earn C or better do not spend significantly more time outside of class doing coursework.

6) confidence interval and effect size

please revert for any doubts....