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Finding the Fourth Proportional to 688.70, 1,030.35 and 623.90

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Solution

The fourth proportional to 688.70, 1,030.35 and 623.90 is: 933.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    688.70 : 1,030.35 = 623.90 : x
  2. Step 2: Convert to fraction form
    688.70/1,030.35 = 623.90/x
  3. Step 3: Cross multiply
    688.70x = 1,030.35 × 623.90
  4. Step 4: Simplify right side
    688.70x = 642,835.37
  5. Step 5: Solve for x
    x = 642,835.37/688.70
  6. Step 6: Final answer
    x = 933.40

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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.