Interpreting Histogram Simple Question

[eutas1]

I am not sure why the answer is B? I thought it was C by adding the frequencies for the 4-6, 7-9, and 10-12 bars and then divide by 100: (22 + 23 + 15) / 100 = 0.6

 

[Dr.Peterson]

I am not sure why the answer is B? I thought it was C by adding the frequencies for the 4-6, 7-9, and 10-12 bars and then divide by 100: (22 + 23 + 15) / 100 = 0.6

That would be correct if it were 3 < x <= 12.

They are evidently supposing that the 10-12 interval is equally divided among 10, 11, and 12 in order to make a reasonable estimate.

 

[eutas1]

That would be correct if it were 3 < x <= 12.

They are evidently supposing that the 10-12 interval is equally divided among 10, 11, and 12 in order to make a reasonable estimate.

Ah, I see! Thank you very much!