SAT Mathematics Practice Test 4

The equation that models the normal systolic blood pressure, in millimeters of mercury, for a male x years old,p=

x+220

2

,can be rewritten as P=

1

2

x+110 For each increase of 1 yearin age, the value of x increases by 1; hence, P becomes

1

2

(x+1)+110=(

1

2

x+110)+

1

2

.That is, P increases by

1

2

millimeter of mercury. Either the fraction

1

2

or its decimal equivalent, .5, may be gridded as the correct answer.