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Finding the Fourth Proportional to 687.66, 1,030.10 and 339.95

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Solution

The fourth proportional to 687.66, 1,030.10 and 339.95 is: 509.23

Step by Step Solution

  1. Step 1: Write the proportion equation
    687.66 : 1,030.10 = 339.95 : x
  2. Step 2: Convert to fraction form
    687.66/1,030.10 = 339.95/x
  3. Step 3: Cross multiply
    687.66x = 1,030.10 × 339.95
  4. Step 4: Simplify right side
    687.66x = 350,175.64
  5. Step 5: Solve for x
    x = 350,175.64/687.66
  6. Step 6: Final answer
    x = 509.23

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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.