Question

Suppose you measured systolic blood pressure (unit: mmHg) of 20 individuals aged 40 to 60 living in LA, and obtained the following: 103, 115, 120, 123, 123, 128, 129, 130, 130, 132, 133, 137, 140, 140, 142, 148, 161, 165, 172, 195

1. Construct a frequency distribution with density using the intervals corresponding to the American Heart Association’s blood pressure categories for systolic blood pressure: normal: [100,120), elevated: [120,130), hypertension stage 1: [130,140), hypertension stage 2: [140,180), and hypertensive crisis: [180,200).

2. Construct the most appropriate histogram using the intervals defined in your frequency distribution in Problem 3.

Answer 1

Category	Class	Frequency
Normal	100-120	3
Elevated	120-130	6
Hypertension Stage 1	130-140	5
Hypertension Stage 2	140-180	5
Hypertensive crisis	180-200	1
		20

Histograms are used for easier visual representation of the data.

Continuous class are one of the features of it. The upper class limit is inclusive of the frequency, hence eg 140 would be included in 130 - 140 and not 140 - 180.