Springville Herald Case 3

SH 9 – p. 307

Data | | | |

Null Hypothesis = | 0.97 | | | |

Level of Significance | 0.05 | | | |

Sample Size | 50 | | | |

Sample Mean | 0.95872 | | | |

Sample Standard Deviation | 0.155968 | | | |

| | | | |

Intermediate Calculations | | | |

Standard Error of the Mean | 0.022057206 | | | |

Degrees of Freedom | 49 | | | |

t Test Statistic | -0.511397498 | | | |

| | | | |

Lower-Tail Test |   | | Calculations Area |

Lower Critical Value | -1.676550893 | | For one-tailed tests: |

p-Value | 0.305684815 | | TDIST value | 0.305685 |

Do not reject the null hypothesis |   | | 1-TDIST value | 0.694315 |

| | | | |

There is insufficient evidence to conclude that the mean blackness for all Springville Herald newspapers is less than .97, therefore we do not need to change any practices in the production department with regard to the darkness of the ink.

10.1

Reject

Reject

Reject

Reject

2.14

2.14

-2.14

-2.14

tSTAT = 3.59

tSTAT = 3.59

t-Test: Paired Two Sample for Means | | |

| | |

  | Early | Late |

Mean | 36.74 | 40.72 |

Variance | 8.896857143 | 12.72457143 |

Observations | 15 | 15 |

Pearson Correlation | 0.152712748 | |

Hypothesized Mean Difference | 0 | |

df | 14 | |

t Stat | -3.596283002 | |

P(T<=t) one-tail | 0.001459969 | |

t Critical one-tail | 1.761310136 | |

P(T<=t) two-tail | 0.002919939 | |

t Critical two-tail | 2.144786688 |   |

Since it is easier to run the t-Test for a specific number, we set our null hypothesis as:

H0: μ=0 (meaning, there is no difference in call length at a certain time of day)

H1: μ≠0 (meaning there is a difference in call length at a certain time of day)

Based on the data above there is sufficient evidence to reject our null hypothesis that the time a Springville Herald telemarketer calls a potential customer makes no impact on the length of call. In doing so, it proves...