Answer:

A. 6

Step-by-step explanation:

To find the first quartile, we need to arrange the data set in ascending order and then determine the value that separates the lowest 25% of the data from the rest of the set.

Arranging the data set in ascending order:

• 4, 5, 6, 8, 9, 11, 12, 13, 14, 16, 20

Since there are 11 data points in the set, we can use the formula:

• First quartile = (n+1)/4-th value

we get:

• First quartile = (11+1)/4-th value
• First quartile = 3rd value

The third value in the data set is 6, so the first quartile is 6.

Therefore, the first quartile of the number of customers who came each hour in a day at Balaluhan in Tagaytay City is 6