Uncompleted Assignment

Q1. Method 1: Scatter Diagram

Figure 1:Practicality vs Road Handling

The scatter diagram is plotted with Road handling on the X axis and Practicality on the Y-axis. A polynomial trend line is plotted with order of 3.The data can be divided into 2 sections: Before and after the 4.65 mark for road handling.

Before the 4.65 mark for road handling, the general trend suggests that cars with higher road handling ratings tend to have a lower practicality rating implying a negative relationship. The relationship also seems to become weaker as Road Handling score increases. This might suggest that improved road handling may not be the most critical component to improving practicality. However, if we focus on cars with road handling scores of 4.65 and above, there seems to be a weak positive relationship. Hence, the relationship between road handling and practicality is weak due to the high number of points above and below the trend line and that there might not even be an apparent cause and effect relationship that exists between the two.

Q2.Method 2: Two-Sample t-Test with unknown and unequal variances

This question examines the link between car sales and overall ranking (position).

To assist in the testing, the data has been split into 2 sample groups as shown by the tables below:

Top 5 ranking cars Next 5 ranking cars

Name of car | Position | Sales of top 5 ranking cars | | Name of car | Position | Sales of next 5 ranking cars |

| Overall | | | | Overall | |

Audi A3 MKIII | 27 | 3731 | | Ford Focus | 65 | 7944 |

Volkswagen Golf | 30 | 4880 | | Fiat 500 | 87 | 2868 |

Mercedes-Benz C Class | 42 | 2868 | | Volkswagen Polo | 167 | 3620 |

Nissan Qashqai | 46 | 3789 | | Vauxhall Astra | 172 | 3187 |

Ford Fiesta | 52 | 8504 | | Vauxhall Corsa | 175 | 4886 |

In this 2 sample t –test, the variances are assumed to be unknown and unequal. The objective of the test is to find out if there is a...