Home / 492.90-684.78-488.40

Finding the Fourth Proportional to 492.90, 684.78 and 488.40

Calculator

Solution

The fourth proportional to 492.90, 684.78 and 488.40 is: 678.53

Step by Step Solution

  1. Step 1: Write the proportion equation
    492.90 : 684.78 = 488.40 : x
  2. Step 2: Convert to fraction form
    492.90/684.78 = 488.40/x
  3. Step 3: Cross multiply
    492.90x = 684.78 × 488.40
  4. Step 4: Simplify right side
    492.90x = 334,446.55
  5. Step 5: Solve for x
    x = 334,446.55/492.90
  6. Step 6: Final answer
    x = 678.53

Related Problems

Find fourth proportional to 246.45, 342.39 and 244.20
Half scale
Find fourth proportional to 985.80, 1,369.56 and 976.80
Double scale
Find fourth proportional to 493.90, 686.17 and 489.40
Similar ratio
Find fourth proportional to 739.35, 1,027.17 and 732.60
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.39) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.