Given a relative frequency histogram for the systolic blood pressure readings.
We will find the percentage of the people who had a systolic blood pressure reading between 110 and 139
As shown:
The percentage of people who had a systolic blood pressure reading between 110 and 119 = 0.35
The percentage of people who had a systolic blood pressure reading between 120 and 129 = 0.25
The percentage of people who had a systolic blood pressure reading between 130 and 139 = 0.15
So, the answer will be = 0.35 + 0.25 + 0.15 = 0.75
So, the answer will be option 3) 75%