Hypothesis Testing 1

Question 1

Correlation

Answer 1

Any observed relationship between two variables

Question 2

Independent

Answer 2

No relationship between two variables

Question 3

What may cause a correlation between variables X and Y?

Answer 3

• Variation in X causes variation in Y
• Variation in Y causes variation in X
• Variation in X and Y is caused by some third factor
• Chance

Question 4

Where are variables plotted on a scatter graph?

Answer 4

• Independent on X

- Dependent on Y axis

Question 5

What are the types of relationships between variables?

Answer 5

• Linear
• Quadratic
• Logarithmic

Question 6

Statistical estimate of relationship between two variables

Answer 6

Interval and ratio scale= correlation coefficient

Question 7

The range of correlation coefficient values

Answer 7

-1 and 1
0= no relationship
1= positive
-1= negative

Question 8

Anscombe’s quartet

Answer 8

Demonstrates the importance of graphing data before statistical analysis
-Similar statistical data may be misleading without graphs
-Importance of outliers
Correlation coefficient ASSUMES THERE IS LINEAR RELATIONSHIP

Question 9

Correlation coefficient for sample estimation

Answer 9

Pearson’s coefficient

Question 10

What are the standard p-value thresholds?

Answer 10

• p < 0.05 meaning that there is less than 1 chance in 20 of obtaining the observed result by chance, if the null hypothesis is true
• p < 0.01 less than 1 chance in 100
• p < 0.001 less than 1 in 1000