EXERCISE 27

EXERCISE 27 - Questions to be graded



EXERCISE 27 - Questions to be graded

What are the independent and dependent variables in Figures 2, A, B, and C? How would you describe the relationship between the variables in Figures 2, A, B, and C?

Solution

Figure 2

Independent Variables

Dependent Variables

(A) Systolic Blood Pressure (SBP)

Postnatal Age (Hours)

(B) Diastolic Blood Pressure (DBP)

(C) Mean Blood Pressure (MBP)

Figure 2 show that there exists a positive relationship between the three different levels of blood pressures and postnatal age in hours, for infants with BW(1,000 grams, as the graph between these variables shows an upward trend.

What are the independent and dependent variables in Figures 3, A, B, and C? How would you describe the relationship between the variables in Figures 3, A, B, and C?

Solution

Similarly, figure 3 also shows a positive relationship between the three different levels of BP (i.e. SBP, DBP and MBP) and postnatal age in hours for infants with a BW of 1,001-1,500 grams.

Figure 2

Independent Variables

Dependent Variables

(A) Systolic Blood Pressure (SBP)

Postnatal Age (Hours)

(B) Diastolic Blood Pressure (DBP)

(C) Mean Blood Pressure (MBP)

Was there a significant difference in the intercept for the lines of best fit in Figure 2 from the intercept for the lines of best fit in Figure 3? Provide a rationale for your answer.

Solution

The results in Figure 2 shows that for each instance, the y intercept was significantly lower (p< 0.001) than the value for comparable lines of best fit in infants with BW (1,000 grams; which means that the values of y intercept in Figure 2 are significant than values of y intercept in Figure 3. However, no significant differences in the slopes for the lines of best fit were observed between the two birth weight groups.

Y represents the predicted value of y calculated using the equation Y = a + bx. In Figure 2, the formula for SBP is Y = 43.2 + 0.17x. Identify the y intercept and the slope in this formula. What does x represent in this formula?

Solution

In figure 2, the equation for Systolic Blood Pressure is given as SBP = 43.2 + O.17x.

y intercept

43.2

Slope

0.17

In the given equation x is representing postnatal age in hours. The equation shows that a unit increase in the value of x will increase the Systolic Blood Pressure by 0.17 units.

In the legend beneath Figure 2, the authors give an equation indicating that systolic blood pressure is SBP= 43.2 + 0.17x. If the ...