Data Analytics Module
Lecturer: Hans van der Zwan
Lab 05
Topic: multiple regression


EXERCISE 6.1

From the 236 houses sold in January 2017 in London, 123 had a selling price above 1 mln GBP. Does this give support to the hypothesis that more than 50% of the houses sold in London have a selling price above 1 mln GPB?


EXERCISE 6.2

In the past 70% of the customers were satisfied about the service of a certain company. To improve this an intervention has been made (all employees had to follow a course about friendly behavior).
A few months later in a random sample of 120 customers, 90 were satisfied about the received service. Does this sample result give support to the assumption that the intervention worked out well?


EXERCISE 6.3

Use the data in the file HP_LONDON_JAN19.xlsx.

  1. Test if there is a significant difference between the proportion flats of all houses sold in the BARNET district and in the GREENWICH district.
  2. β€œThe proportion houses with a selling price of more than 1 mln GBP for the category terraced houses is higher than for the category semi-detached houses.”
    Test if the data support this statement.


EXERCISE 6.4

Research sub question: did house prices in London increase in January 2019 relative to the prices of houses sold in 2018.
In 2018 the average selling Price in London was 740,824 GBP, the median was 515,000 GPB and 15.4% of the houses sold had a selling price above 1 mln GBP.

  1. This research question has been operationalized by stating the hypothesis that the proportions of houses with a selling price of more than 1 mln GBP in London district in January 2019 was more than 15.4%.
    Perform this test and report the conclusion as it would be done in a scientific report.
  2. This research question can also be operationalized by stating the hypothesis that the proportions of houses with a selling price of more than 510,000 GBP (the median in 2018) in London in January 2019 was more than 50%.
    Perform this test and report the conclusion as it would be done in a scientific report.


EXERCISE 6.5

Operationalize the following research questions using a binomial test.

  1. Do female students at THUAS score better for statistics assignments as male students?
  2. Did the quality of the service of an IT helpdesk in the company increased after the intervention?
  3. Did the number of accidents in the Netherlands in which electric bicycles were involved increase in 2018 compared with 2017?


EXERCISE 6.6

Researching air quality in the major Dutch cities.
Data file: Air quality Netherlands 2016.
Use a two-sample proportion test to test whether the proportion days with an average PM10-value above 30 \(\mu g\) per m3 in Rotterdam in 2016 is significantly higher than in The Hague.