Weekly Homework #7

- In what sense is the linear correlation coefficient the â€œstatistical essence of scienceâ€? Give a specific answer.
- Which of the following relationships is likely to be direct and which is inverse? Explain your answer.
- Amount of TV viewing per week and college GPA
- Age and visual ability
- Advertising money and sales volume within a company
- Height of parents and height of their children
- Economic frustrations and social class

- In your own words, describe the relationship between z scores and correlation.
- Examine the following data set and answer the questions:

Daughterâ€™s height (y) |
Motherâ€™s height (x) |

60 |
62 |

66 |
67 |

65 |
64 |

66 |
66 |

67 |
65 |

63 |
63 |

69 |
65 |

63 |
61 |

61 |
59 |

65 |
67 |

- Draw a scatterplot for these data. Comment on whether or not it looks like there is a linear relationship and, if so, whether it is positive or negative.
- Using Excel, find the correlation between the motherâ€™s heights. Do the value and the sign make sense based on the scatterplot.
- Using Excel, find the intercept and slope for the regression equation.
- The equation you found in part c might be useful for predicting the height before the daughter is fully grown. Use the equation to predict the height of the daughter of a mother who is 63 inches tall.

5. View the following source and answer the questions.

- What two variables were measured for each person to provide this result?
- Explain what is meant by r = .44.
- What is meant by the word significantly as it used in the article?
- The authors did not provide a regression equation relating the two variables. If a regression equation were to be found for the two variables, which one do you think would be the explanatory variable?