The large data set Quiz

1. Which variable is discrete?

• A. Engine size in litres
• B. Number of doors
• C. Temperature
• D. Fuel consumption

2. A sample has $n=10$, $\sum x=80$ and $\sum x^2=700$. Find the standard deviation.

• A. $\sqrt{6}$
• B. $\sqrt{70}$
• C. $\sqrt{10}$
• D. $6$

3. $Q_1=40$ and $Q_3=52$. Which value is an outlier by the $1.5\times$ IQR rule?

• A. 58
• B. 66
• C. 72
• D. 30

4. A student replaces missing temperatures by 0 before finding the mean. What happens?

• A. Only the median changes
• B. The mean is too high
• C. The mean is unchanged
• D. The mean is too low

5. Which statement about skew is correct?

• A. Mean below median suggests positive skew
• B. Mean above median suggests positive skew
• C. Mean equal to range suggests skew
• D. IQR above SD suggests skew