Home / 472.78-705.37-420.80

Finding the Fourth Proportional to 472.78, 705.37 and 420.80

Calculator

Solution

The fourth proportional to 472.78, 705.37 and 420.80 is: 627.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    472.78 : 705.37 = 420.80 : x
  2. Step 2: Convert to fraction form
    472.78/705.37 = 420.80/x
  3. Step 3: Cross multiply
    472.78x = 705.37 × 420.80
  4. Step 4: Simplify right side
    472.78x = 296,817.59
  5. Step 5: Solve for x
    x = 296,817.59/472.78
  6. Step 6: Final answer
    x = 627.82

Related Problems

Find fourth proportional to 236.39, 352.68 and 210.40
Half scale
Find fourth proportional to 945.55, 1,410.73 and 841.60
Double scale
Find fourth proportional to 473.78, 706.86 and 421.80
Similar ratio
Find fourth proportional to 709.16, 1,058.05 and 631.20
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.