Question

The box plot shows information about the marks scored in a test. Nobody gained 30, 48 or 70 marks. 120 students gained less than 70 marks. How many students gained more than 48 marks?

Answer 1

Answer:

50% of all students scored more than 48 marks.

Step-by-step explanation:

1) The baseline of the box, in a box plot is the first quartile, the line in the middle is the median or Q2 and the last line (or top line) is the third quartile. Namely,

$Q_{1}=30, Q_{2}=48 \:and\:Q_{3}=70$

2) The Question says "nobody took 30, 48 or 70 as their grades. But 120 students gained less than 70", i.e. 120 are within the 75% of the sample.

3) If $Q_{2}=48$ then 50% of the students scored more than 48. And 50% of the students scored less than 48. That is also known as the Median.

So 50%, the half of all students scored more than 48 marks.