The equation is y= 0.58755X + 7.16117

If the systolic pressures of two patients differ by 19 millimeters, by how much would you predict their diastolic pressures to differ? Round the answer to three decimal places.

3 answers

To solve this problem, we can start with the given equation for \( y \), which represents diastolic pressure in terms of \( X \), which represents systolic pressure:

\[ y = 0.58755X + 7.16117 \]

Given that the difference in systolic pressures of two patients is \( 19 \) mm, we can express their systolic pressures as \( X_1 \) and \( X_2 \):

\[ |X_2 - X_1| = 19 \]

Let's find the difference in diastolic pressures (\( y_2 - y_1 \)) corresponding to the difference in systolic pressures \( X_2 - X_1 \).

The diastolic pressures can be expressed as:

\[ y_1 = 0.58755X_1 + 7.16117 \]

\[ y_2 = 0.58755X_2 + 7.16117 \]

Now, subtract the two equations to find the difference in diastolic pressures:

\[ y_2 - y_1 = (0.58755X_2 + 7.16117) - (0.58755X_1 + 7.16117) \]

This simplifies to:

\[ y_2 - y_1 = 0.58755(X_2 - X_1) \]

We need to calculate \( |y_2 - y_1| \):

\[ |y_2 - y_1| = 0.58755 |X_2 - X_1| \]

With \( |X_2 - X_1| = 19 \):

\[ |y_2 - y_1| = 0.58755 \times 19 \]

Calculating this gives:

\[ |y_2 - y_1| = 11.15645 \]

Finally, rounding this to three decimal places:

\[ |y_2 - y_1| \approx 11.156 \]

Thus, the predicted difference in diastolic pressures is approximately 11.156 mm.

Predict the diastolic pressure for a patient whose systolic pressure is 125 millimeters. Round the answer to one decimal place.

To predict the diastolic pressure for a patient with a systolic pressure of \(X = 125\) mm, we can use the given equation:

\[ y = 0.58755X + 7.16117 \]

Substituting \(X\) with \(125\):

\[ y = 0.58755(125) + 7.16117 \]

Calculating the first part:

\[ 0.58755 \times 125 = 73.44375 \]

Now, adding the constant:

\[ y = 73.44375 + 7.16117 = 80.60492 \]

Rounding this to one decimal place:

\[ y \approx 80.6 \]

Therefore, the predicted diastolic pressure for a patient with a systolic pressure of 125 mm is 80.6 mm.