What are m and b and what do they represent for the cost function

Therefore the answer is 20.

Step-by-step explanation:

We know that

class interval = range / number of classes

But here number of classes is not given , so we use the formula

class interval = range / ( 1+ 3.322 log N)

where , range =maximum - minimum = 220-100 = 120

N= number of observations = 50

class interval = 120 / ( 1+ 3.322 * log 50) = 18.06

Rounding up to a convinient number

Thus , class intervai = 20

Therefore the answer is 20.