Explanation

• The semi-interquartile range (SIQR) is calculated as half of the interquartile range (IQR), which is the difference between the third quartile (Q3) and the first quartile (Q1).
• So, SIQR = (Q3 - Q1) / 2
• Given Q1 = 78 and Q3 = 48, we need to subtract Q1 from Q3, but then take the absolute value because Q3 is less than Q1 in this case:
• SIQR = |48 - 78| / 2 = |-30| / 2 = 30 / 2 = 15
• Therefore, the value of the semi-interquartile range is 15.