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Finding the Fourth Proportional to 621, 931.21 and 313

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Solution

The fourth proportional to 621, 931.21 and 313 is: 469.35

Step by Step Solution

  1. Step 1: Write the proportion equation
    621 : 931.21 = 313 : x
  2. Step 2: Convert to fraction form
    621/931.21 = 313/x
  3. Step 3: Cross multiply
    621x = 931.21 × 313
  4. Step 4: Simplify right side
    621x = 291,468.73
  5. Step 5: Solve for x
    x = 291,468.73/621
  6. Step 6: Final answer
    x = 469.35

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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.