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Finding the Fourth Proportional to 1,221.29, 1,830.65 and 399.35

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Solution

The fourth proportional to 1,221.29, 1,830.65 and 399.35 is: 598.60

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,221.29 : 1,830.65 = 399.35 : x
  2. Step 2: Convert to fraction form
    1,221.29/1,830.65 = 399.35/x
  3. Step 3: Cross multiply
    1,221.29x = 1,830.65 × 399.35
  4. Step 4: Simplify right side
    1,221.29x = 731,070.08
  5. Step 5: Solve for x
    x = 731,070.08/1,221.29
  6. Step 6: Final answer
    x = 598.60

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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.