Question Details

(solution) Hello there! I'm having difficulty completing my statistics


Hello there! I'm having difficulty completing my statistics problem set for my political science course. I completed problems 1 & 2 relatively easily, but I'm struggling with the rest of the assignment. Help please?


Name:_______________________________ GSI:________________________________ Political Science 3 Homework # 4 Note: It is highly recommended that you show your work. This means setting up the problem

 

by writing out the equation(s) being used (if an equation is involved) and showing that you

 

know what to plug into the equation(s). Partial credit may be given for incorrect answers if the

 

work shows that you made a simple error. On the questions that specifically ask you to show

 

your work, full credit will not be given without it.

 

1. A recent poll asked people whether they supported passing a constitutional

 

amendment to ban burning of the national flag using a 1 to 100 scale.?1? means that

 

they do not support passing the amendment at all and ?100? means they support it

 

completely. The sample was random (from the population of US adults) and included

 

886 people, 350 of whom were women, and 536 of whom were men. The mean score for

 

women was 82.6, while the mean score for men was 78.4.

 

a) [4 points] Is the difference in means statistically significant at the 5% level? Assume

 

the standard deviation for both men and women is 3.5. Show your work.

 

b) [4 points] If the standard deviation for men is 1.4 and the standard deviation for

 

women is 1.2, is the difference in means statistically significant at the 5% level?

 

Show your work. 2. The following table is based on a sample of high school seniors and their parents. The

 

data comes from a study conducted by Jennings and Niemi, in which they explore the

 

party identification of parents and their children. a) [2 points] What is the percentage of students who share the same party identification

 

as their parents? 1 b) [3 points] What is the relationship between students? party identification and the

 

party identification of their parents? (In other words, do students generally follow

 

their parents? party identification, or not?)

 

c) [4 points] Based on these data, can we say if the relationship is causal? Explain your

 

answer.

 

d) [6 points] Suppose you were exploring the hypothesis that there is a relationship

 

between parents? and children?s party identification. Would we be correct in

 

inferring that such a relationship also exists in the population? Explain your answer.

 

What is the probability that any relationship we found is due to pure chance? 3. Tens of thousands of people die each year on America?s highways. How can the

 

number of fatalities be reduced? In the next few questions, we explore trends in traffic

 

fatalities across the 50 states and potential solutions to the problem. Consider the table

 

below, indicating summary statistics of the number of traffic deaths per million miles

 

driven across all 50 states, in 1985 and 1992.

 

Variable |

 

Obs

 

Mean

 

Std. Dev.

 

Min

 

Max

 

-------------+-------------------------------------------------------traffic_1985 |

 

50

 

2.294

 

.6079104

 

1.9

 

4.4

 

traffic_1992 |

 

50

 

1.744

 

.449108

 

1

 

2.7 a) [2 points] What is the average change across states between 1985 and 1992 in

 

traffic deaths per million miles driven?

 

b) [4 points] Assume that these observations represent a random sample of all

 

years. How likely would we get the average change found in part (a) if the true

 

difference in the population were actually zero? Show your work.

 

c) [4 points] Can we reasonably claim that there is a difference in traffic fatalities

 

between 1985 and 1992? Explain your reasoning. 4. Continuing with your study of traffic fatalities, you have been charged with figuring

 

out what policy would best curb the death rate. You discover that states have tried a

 

number of solutions in the past, including raising the drinking age to 21, mandating the

 

use of seat belts and helmets, and setting a maximum speed limit of 65 miles per hour.

 

These various initiatives make you wonder whether states that pass one of these

 

measures are also more likely to pass another. You therefore construct the table on the

 

following page, which indicates how many states have passed mandatory seat belt laws

 

and/or have imposed a 65 mile per hour speed cap. 2 | Mandatory seatbelt law

 

65 MPH |

 

Cap

 

|

 

no

 

yes |

 

Total

 

-----------+----------------------+---------no |

 

0

 

8 |

 

8

 

yes |

 

8

 

24 |

 

32

 

-----------+----------------------+---------Total |

 

8

 

32 |

 

40 a) [2 points] What percentage of states has passed both seat belt laws and a speed limit

 

law? Show your work.

 

b) [2 points] Of the states that have imposed a 65 MPH speed cap, what percentage

 

does not mandate seat belts? Show your work.

 

c) [4 points] Test the claim that states which pass mandatory seat belt laws tend also to

 

impose 65 MPH speed limits. Is there a relationship? Why or why not?

 

5. [5 points] You hate the laws imposing 65 MPH speed limits, but are nonetheless curious

 

as to whether the law actually reduces highway deaths. Using information in the table

 

below, perform an appropriate test to determine whether speed limits reduce traffic

 

deaths or not. Explain your reasoning.

 

-> There IS a speed limit law.

 

Variable |

 

Obs

 

Mean

 

Std. Dev.

 

Min

 

Max

 

-------------+-------------------------------------------------------traffic_1992 |

 

8

 

1.5

 

.3338092

 

1.1

 

2.1

 

-> There IS NOT a speed limit law.

 

Variable |

 

Obs

 

Mean

 

Std. Dev.

 

Min

 

Max

 

-------------+-------------------------------------------------------traffic_1992 |

 

32

 

1.909524

 

.4410683

 

1

 

2.7 6. How much student improvement takes place in PS3? One way to examine this question is to look at exam performance over time. On the following page is a scatterplot relating exam scores on the first two midterms, with a line of best fit drawn through the points. Each point represents a student in the class. 3 1

 

.9

 

.8

 

Midterm 2 Score

 

.4 .5 .6 .7

 

.3

 

.2

 

.1

 

0

 

0 .1 .2 .3 .4

 

.5

 

.6

 

Midterm 1 Score .7 .8 .9 1 a) [2 points] Describe in a few sentences what this trend implies about the association between scores on the first midterm and scores on the second midterm. b) [4 points] To what extent does this graph indicate an improvement in scores between the two midterms? Explain how you arrived at your answer. 7. The table below shows the results of a bivariate regression of midterm 2 scores on midterm 1 scores (using point totals rather than fractions, and performed in Stata, a popular statistics package). Source |

 

SS

 

df

 

MS

 

-------------+-----------------------------Model | 14335.1038

 

1 14335.1038

 

Residual | 22680.6453

 

280 81.0023045

 

-------------+-----------------------------Total | 37015.7491

 

281 131.728645 Number of obs

 

F( 1,

 

280)

 

Prob > F

 

R-squared

 

Adj R-squared

 

Root MSE =

 

=

 

=

 

=

 

=

 

= 282

 

176.97

 

0.0000

 

0.3873

 

0.3851

 

9.0001 -----------------------------------------------------------------------------mid2 |

 

Coef.

 

Std. Err.

 

t

 

P>|t|

 

[95% Conf. Interval]

 

-------------+---------------------------------------------------------------mid1 |

 

.6251181

 

.0469905

 

13.30

 

0.000

 

.5326186

 

.7176177

 

_cons |

 

24.45228

 

2.639302

 

9.26

 

0.000

 

19.25689

 

29.64767 4 a) [3 points] Is the relationship between scores on midterm 1 and midterm 2 statistically significant at the .05 level? Why or why not? What sampling assumptions have to be made to conclude this? b) [5 points] Using the information in the table, compute a 99% confidence interval for midterm 1 (mid1). Is the relationship between scores on midterm 1 and midterm 2 statistically significant at the .01 level? Why or why not? c) [5 points] Suppose a student got 50 points on midterm 1. What would the expected performance of that student be according to this bivariate model? Explain how you arrived at your answer. 5

 


Solution details:

Pay using PayPal (No PayPal account Required) or your credit card . All your purchases are securely protected by .
SiteLock

About this Question

STATUS

Answered

QUALITY

Approved

DATE ANSWERED

Sep 13, 2020

EXPERT

Tutor

ANSWER RATING

GET INSTANT HELP/h4>

We have top-notch tutors who can do your essay/homework for you at a reasonable cost and then you can simply use that essay as a template to build your own arguments.

You can also use these solutions:

  • As a reference for in-depth understanding of the subject.
  • As a source of ideas / reasoning for your own research (if properly referenced)
  • For editing and paraphrasing (check your institution's definition of plagiarism and recommended paraphrase).
This we believe is a better way of understanding a problem and makes use of the efficiency of time of the student.

NEW ASSIGNMENT HELP?

Order New Solution. Quick Turnaround

Click on the button below in order to Order for a New, Original and High-Quality Essay Solutions. New orders are original solutions and precise to your writing instruction requirements. Place a New Order using the button below.

WE GUARANTEE, THAT YOUR PAPER WILL BE WRITTEN FROM SCRATCH AND WITHIN A DEADLINE.

Order Now