Exam_29.01.2018

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gerhi
Beiträge: 2
Registriert: 23.10.2017, 15:31

Exam_29.01.2018

Beitrag von gerhi » 29.01.2018, 16:50

First Page:
1)
Several statements which were either true/false (most were doable, some were tricky).
Similar like:
*The 2 sample-t test compares the medians of two contributions. T/F
*The loadings of a principal component are always greater than 1. T/F
...

2)
You are measuring your bloodpressure everyday. Weakly and Monthly values are the mean of the daily measurements, so 7 and 4*7 measurements (approximately) - 4 Statements were given, again tick true/false.

Can't remeber preicisly, but the questions were: How the means and variances differ between monthly and weekly measurements and what distributions were to expect.

Second Page:

3) You wan't to check if fertilization of your 5 fields leads to a difference, in terms of crop yield.
You have 5 neighbouring fields, each on is divided into 16 sections. For each section you know the crop yield. As every field was fertilized differently, estimate if this has an impact in terms of crop yield. Which tests (+ prerequisites) do you use?

a) calculate mean and variance of each field (from the sections)
b) check each field for normal distribution
c) check if the variances are equal
d) use ANOVA, H0: all means are the same

4) Properties of your MLR you want to check:
a) How can you express the fitness of the model?
b) Which variables contribute in a positive manner to the model?
c) How can you detect collinearity?

5) A scatter plot was given, create a Dendogram.

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