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Finding the Fourth Proportional to 904.20, 1,356.30 and 520.20

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Solution

The fourth proportional to 904.20, 1,356.30 and 520.20 is: 780.30

Step by Step Solution

  1. Step 1: Write the proportion equation
    904.20 : 1,356.30 = 520.20 : x
  2. Step 2: Convert to fraction form
    904.20/1,356.30 = 520.20/x
  3. Step 3: Cross multiply
    904.20x = 1,356.30 × 520.20
  4. Step 4: Simplify right side
    904.20x = 705,547.26
  5. Step 5: Solve for x
    x = 705,547.26/904.20
  6. Step 6: Final answer
    x = 780.30

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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.