From descriptive to inferential statistics

How can the graph be improved?

• Do not cut y-axis

• Use pie chart

• Order bars by year

• Use stacked bar chart

Our sample is: 1,3,5,8,1000.

Which of the following statements is correct:

• The median is smaller than the mean

• The median is larger than the mean

• The median equals the mean

• The interquartile range equals the standard deviation

Our observation is -2, the mean 1 and the standard deviation 2. What is the Z score of the observation?

• -1

• 1

• 0

• -1.5

Which histogram is from a normally distributed population?

• 
• 
• 
• 

The weight of all students has mean of 65 and a standard deviation of 10. We sample 100 students. What is the (approximate) probability that the sample mean is larger than 65?

• 0

• 5%

• 25%

• 50%

Alexander has computed 2000 confidence intervals with confidence level of 95% in his life. How many confidence intervals did not include the true parameter?

• approximately 0

• approximately 5

• approximately 50

• approximately 100

We compute a test with significance level 5%. How large is the probability of type 1 error?

• approximately 0%

• approximately 5%

• approximately 95%

• It depends on the test

We measure the height of father and sons (in inch) and apply a two sample t-test. What can we conclude?

• Father and sons are approximately equally large

• There is a significant difference in the height of father and sons

• The difference in height of father and sons is 8 inch

• We cannot reject the nullhypothesis

We measure the height of fathers and theirs sons and compute a correlation test. What can we deduce?

• The height of fathers and their sons is independent

• There is a strong correlation

• There is a moderate correlation

• We cannot reject the nullhypothesis

We asked students whether they liked the course and whether they like mathematics. The we performe a chi-square test of independence. What can we conclude?

• Students who like mathematics like also the course

• We cannot reject the nullhypothesis

• There is no dependence between liking the course and liking math

• Students who hate math like the course