Question

1. In a class of 20 students, 13 students are exactly 5 feet 6 inches tall, whereas the rest of the class is over 5 feet 6 inches. Andrew, who is 5 feet 10 inches tall, joins the class.
Which of the following statements is true about the mean? Explain as well.
i Mean height of the class increases ii. Mean height of the class stays the same iii. Mean height of the class goes down iv. Cannot tell

Answer 1

Earlier there were 20 students and exactly 13 were 5 feet 6 inches tall, whereas the rest of the class is over 5 feet 6 inches.

Andrew, who is 5 feet 10 inches tall, joins the class.

Now, there are 21 students and exactly 13 were 5 feet 6 inches tall, whereas the rest of the class is over 5 feet 6 inches.

Since, we do not know the previous mean height of the class if it was grater than 5 feet 10 inches or lesser. We can not interpret any change in mean

iv. Cannot tell