Do left handed starting pitchers pitch the same number of innings per game on average as right handed starting pitchers?  A researcher looked at eleven randomly selected left

MATLAB: An Introduction with Applications
6th Edition
ISBN:9781119256830
Author:Amos Gilat
Publisher:Amos Gilat
Chapter1: Starting With Matlab
Section: Chapter Questions
Problem 1P
icon
Related questions
Question
100%

Do left handed starting pitchers pitch the same number of innings per game on average as right handed starting pitchers?  A researcher looked at eleven randomly selected left handed starting pitchers' games and ten randomly selected right handed pitchers' games. The table below shows the results.

Left:  5     5     6     7     7     7     6     7     6     4

Right:  8     6     8     7     7     6     8     8     7

Assume that both populations follow a normal distribution.  What can be concluded at the the αα = 0.05 level of significance level of significance?

For this study, we should use Select an answer z-test for the difference between two population proportions z-test for a population proportion t-test for the difference between two dependent population means t-test for a population mean t-test for the difference between two independent population means 

  1. The null and alternative hypotheses would be:   
  2.   

 H0:H0:  Select an answer p1 μ1  Select an answer > = ≠ <  Select an answer μ2 p2  (please enter a decimal)   

 H1:H1:  Select an answer μ1 p1  Select an answer = > ≠ <  Select an answer p2 μ2  (Please enter a decimal)

  1. The test statistic ? z t  =  (please show your answer to 3 decimal places.)
  2. The p-value =  (Please show your answer to 4 decimal places.)
  3. The p-value is ? ≤ >  αα
  4. Based on this, we should Select an answer reject fail to reject accept  the null hypothesis.
  5. Thus, the final conclusion is that ...
    • The results are statistically insignificant at αα = 0.05, so there is insufficient evidence to conclude that the population mean innings per game for left handed starting pitchers is not the same as the population mean innings per game for right handed starting pitchers.
    • The results are statistically significant at αα = 0.05, so there is sufficient evidence to conclude that the population mean innings per game for left handed starting pitchers is not the same as the population mean innings per game for right handed starting pitchers.
    • The results are statistically insignificant at αα = 0.05, so there is statistically significant evidence to conclude that the population mean innings per game for left handed starting pitchers is equal to the population mean innings per game for right handed starting pitchers.
    • The results are statistically significant at αα = 0.05, so there is sufficient evidence to conclude that the mean innings per game for the eleven left handed starting pitchers that were looked at is not the same as the mean innings per game for the ten right handed starting pitchers that were looked at.
  6. Interpret the p-value in the context of the study.
    • If the population mean innings per game for left handed starting pitchers is the same as the population mean innings per game for right handed starting pitchers and if another 10 lefties and 9 righties are observed then there would be a 1.2% chance that the mean number of innings per game for the 10 lefties would differ by at least 1.2 innings from the mean innings per game for the 9 righties.
    • If the sample mean innings per game for the 10 lefties is the same as the sample mean innings per game for the 9 righties and if another another 10 lefties and 9 righties are observed then there would be a 1.2% chance of concluding that the mean innings per game for the 10 lefties and the 9 righties differ by at least 1.2 innings per game
    • There is a 1.2% chance that the mean innings per game for the 10 lefties differs by at least 1.2 innings per game compared to the 9 righties.
    • There is a 1.2% chance of a Type I error.
  7. Interpret the level of significance in the context of the study.
    • There is a 5% chance that your team will win whether the starting pitcher is a lefty or a righty. What you really need is better pitchers.
    • If the population mean innings per game for left handed starting pitchers is the same as the population mean innings per game for right handed starting pitchers and if another 10 lefties and 9 righties are observed then there would be a 5% chance that we would end up falsely concluding that the population mean innings per game for the lefties is not the same as the population mean innings per game for the righties
    • If the population mean innings per game for lefties is the same as the population mean innings per game for righties and if another 10 lefties and 9 righties are observed, then there would be a 5% chance that we would end up falsely concluding that the sample mean innings per game for these 10 lefties and 9 righties differ from each other.
    • There is a 5% chance that there is a difference in the population mean innings per game for lefties and righties.
Expert Solution
trending now

Trending now

This is a popular solution!

steps

Step by step

Solved in 4 steps with 4 images

Blurred answer
Knowledge Booster
Point Estimation, Limit Theorems, Approximations, and Bounds
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, statistics and related others by exploring similar questions and additional content below.
Similar questions
  • SEE MORE QUESTIONS
Recommended textbooks for you
MATLAB: An Introduction with Applications
MATLAB: An Introduction with Applications
Statistics
ISBN:
9781119256830
Author:
Amos Gilat
Publisher:
John Wiley & Sons Inc
Probability and Statistics for Engineering and th…
Probability and Statistics for Engineering and th…
Statistics
ISBN:
9781305251809
Author:
Jay L. Devore
Publisher:
Cengage Learning
Statistics for The Behavioral Sciences (MindTap C…
Statistics for The Behavioral Sciences (MindTap C…
Statistics
ISBN:
9781305504912
Author:
Frederick J Gravetter, Larry B. Wallnau
Publisher:
Cengage Learning
Elementary Statistics: Picturing the World (7th E…
Elementary Statistics: Picturing the World (7th E…
Statistics
ISBN:
9780134683416
Author:
Ron Larson, Betsy Farber
Publisher:
PEARSON
The Basic Practice of Statistics
The Basic Practice of Statistics
Statistics
ISBN:
9781319042578
Author:
David S. Moore, William I. Notz, Michael A. Fligner
Publisher:
W. H. Freeman
Introduction to the Practice of Statistics
Introduction to the Practice of Statistics
Statistics
ISBN:
9781319013387
Author:
David S. Moore, George P. McCabe, Bruce A. Craig
Publisher:
W. H. Freeman