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Finding the Fourth Proportional to 687.30, 1,030.96 and 646.30

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Solution

The fourth proportional to 687.30, 1,030.96 and 646.30 is: 969.46

Step by Step Solution

  1. Step 1: Write the proportion equation
    687.30 : 1,030.96 = 646.30 : x
  2. Step 2: Convert to fraction form
    687.30/1,030.96 = 646.30/x
  3. Step 3: Cross multiply
    687.30x = 1,030.96 × 646.30
  4. Step 4: Simplify right side
    687.30x = 666,309.45
  5. Step 5: Solve for x
    x = 666,309.45/687.30
  6. Step 6: Final answer
    x = 969.46

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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.