Home / 684.80-945-422.72

Finding the Fourth Proportional to 684.80, 945 and 422.72

Calculator

Solution

The fourth proportional to 684.80, 945 and 422.72 is: 583.34

Step by Step Solution

  1. Step 1: Write the proportion equation
    684.80 : 945 = 422.72 : x
  2. Step 2: Convert to fraction form
    684.80/945 = 422.72/x
  3. Step 3: Cross multiply
    684.80x = 945 × 422.72
  4. Step 4: Simplify right side
    684.80x = 399,470.40
  5. Step 5: Solve for x
    x = 399,470.40/684.80
  6. Step 6: Final answer
    x = 583.34

Related Problems

Find fourth proportional to 342.40, 472.50 and 211.36
Half scale
Find fourth proportional to 1,369.60, 1,890 and 845.44
Double scale
Find fourth proportional to 685.80, 946.38 and 423.72
Similar ratio
Find fourth proportional to 1,027.20, 1,417.50 and 634.08
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.