Home / 56.40-78.03-54.15

Finding the Fourth Proportional to 56.40, 78.03 and 54.15

Calculator

Solution

The fourth proportional to 56.40, 78.03 and 54.15 is: 74.92

Step by Step Solution

  1. Step 1: Write the proportion equation
    56.40 : 78.03 = 54.15 : x
  2. Step 2: Convert to fraction form
    56.40/78.03 = 54.15/x
  3. Step 3: Cross multiply
    56.40x = 78.03 × 54.15
  4. Step 4: Simplify right side
    56.40x = 4,225.32
  5. Step 5: Solve for x
    x = 4,225.32/56.40
  6. Step 6: Final answer
    x = 74.92

Related Problems

Find fourth proportional to 28.20, 39.02 and 27.08
Half scale
Find fourth proportional to 112.80, 156.06 and 108.30
Double scale
Find fourth proportional to 57.40, 79.41 and 55.15
Similar ratio
Find fourth proportional to 84.60, 117.05 and 81.23
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.