Home / 1,278.40-1,917.60-457.60

Finding the Fourth Proportional to 1,278.40, 1,917.60 and 457.60

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Solution

The fourth proportional to 1,278.40, 1,917.60 and 457.60 is: 686.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,278.40 : 1,917.60 = 457.60 : x
  2. Step 2: Convert to fraction form
    1,278.40/1,917.60 = 457.60/x
  3. Step 3: Cross multiply
    1,278.40x = 1,917.60 × 457.60
  4. Step 4: Simplify right side
    1,278.40x = 877,493.76
  5. Step 5: Solve for x
    x = 877,493.76/1,278.40
  6. Step 6: Final answer
    x = 686.40

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1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.