Look at the scatterplot below. does it demonstrate a positive or

Data File 4/Statistics in Educational Research (***** Correct Solution after a while tramp by tramp Calculation *****)


Data File 4


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Chapter Seven



Problem 1)  Look at the scatterplot under.  Does it unfold a direct or disclaiming apposition?  Why? Are there any outliers?  What are they? 




Problem 2)  Look at the scatterplot under.  Does it unfold a direct or disclaiming apposition?  Why? Are there any outliers?  What are they? 





Problem 3)  The subjoined grounds end from your capacity, completion 26 on page 298.  Here is the grounds:



                        Mean daily calories                             Infant Mortality Rate (per 1,000 births)


                        1523                                                    154     


                        3495                                                    6


                        1941                                                    114


                        2678                                                    24


                        1610                                                    107


3443                                                    6


1640                                                    153


3362                                                    7



3429                                                    44


2671                                                    7


  1. For the over grounds frame a scatterplot using SPSS or Excel (Follow instructions on page 324 of your textbook).  What does the scatterplot appearance?  Can you state a model of interdependence? Are there any outliers that you can see?

  2. Using the identical grounds guide a apposition separation using SPSS or Excel.  What is the apposition coefficient?  Is it a vigorous, abstinent or vapid apposition?  Is the apposition insinuateive or not?  If it is what does that medium?   


    Problem 4)


    Bill is doing a device for you in the marketing sequence.  In guideing his separation respecting consumer proceeding and a new emanation that has end out, he tells you the apposition betwixt these two inconstants is 1.09.  What is your response to this separation?


    Problem 5)


    Judy has guideed an separation for her superintendent.  The end she obtained was a apposition coefficient that was disclaiming 0.86.  Judy is promiscuous by this sum and feels that consequently it is disclaiming and not direct, is mediums that it is bad.  You are her superintendent.  How would you exonerate this end for Judy respecting the mediuming of the apposition?


    Problem 6)

               Explain the declaration, “apposition does not denote operativeness.”


    Problem 7)    

                 Using the best-fit sequence under for foretelling, counter-argument the subjoined questions:


    1. What would you forecast the worth of Emanation X in capacity of 150 to be (approximately)?

    2. What would you forecast the worth of Emanation X in capacity of 100 to be (approximately)?




       Problem 8)


      You are animated in tally out if a student’s ACT jaw is a cheerful forecastor of his or her last propaganda pace apex balance (GPA).  You enjoy obtained the subjoined grounds and are going to guide a retirement separation.  Follow the instructions on page 324 of your textcapacity to guide this separation:

      ACT    GPA

       22.0     3.0

      32.0     3.78

      33.0     3.68

      21.0     2.94

      27.0     3.38

      25.0     3.21


      30.0     3.65


      1. What is the R?  What model of interdependence does it designate (strong/weak; direct/negative)?

      2. Go to the coefficients readout.  The ininconstant is the arrest.  Under that is the ACT and that is the extend.  Using the right sequence formula of Y = mx + b, which you procure invent on page 313, you procure now forecast some forthcoming GPA jaws:  In the formula (m) is the extend; (x) is the inconstant that you are looking to use as a forecastor; and (b) is the arrest.  Predict GPA from the subjoined ACT jaws using the retirement equation/right sequence formula (appearance all your exertion):


        1. 20

        2. 25

                     3. 34




Chapter Eight


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Problem 1)


A exemplification of nine students is selected from shapeless the students insertion a  feature exam.  The nine students were asked how ample spell they had late examineing for the exam and the responses (in hours) were as follows:


            18, 7, 10, 13 12, 16, 5, 20, 21

Estimate the medium examine spell of all students insertion the exam. Round your counter-argument to the nearest tenth of an hour, if compulsory.


Problem 2)


Scores on a feature experience enjoy a medium of 64.6.  The classification of exemplification mediums for exemplifications of bigness 100 is recognized after a while a medium of 64.6 and a flag irregularity of 1.9.  Suppose you select a exemplification of bigness 100 of experience jaws and invent that the medium is 63.  What is the z-jaw corresponding to this exemplification medium?


Problem 3)


There are 349 teachers at a propaganda.  Among a exemplification of 110 teachers from this propaganda, 66 enjoy doctorates.  Based on this exemplification, revere the sum of teachers at this propaganda after a whileout doctorates.


Problem 4)


Sample bigness = 400; exemplification medium = 44; exemplification flag irregularity = 16.  What is the brink of hallucination? 


Problem 5)


A exemplification of 64 statistics students at a trivial propaganda had a medium mathematics ACT jaw of 28 after a while a flag irregularity of 4. Estimate the medium mathematics ACT jaw for all statistics students at this propaganda.  Give the 95% dependence balancetime. 


Problem 6)


A synod view guideed to revere the medium worth of houses in a metropolitan area is adapted to enjoy a brink of hallucination of $10,000.  Pilot studies insinuate that the population flag irregularity is $70,000.  Estimate the minimum exemplification bigness needed to revere the population medium after a while the stated correction. 


Problem 7)


A researcher wishes to revere the relation of propaganda students who artifice on exams.  A poll of 490 propaganda students appearanceed that 33% of them had, or planned to, artifice on examinations.  Find the brink of hallucination for the 95% dependence balancetime. 



Data File 4 Statistics in Educational Research