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Finding the Fourth Proportional to 688.80, 1,030.08 and 679.12

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Solution

The fourth proportional to 688.80, 1,030.08 and 679.12 is: 1,015.60

Step by Step Solution

  1. Step 1: Write the proportion equation
    688.80 : 1,030.08 = 679.12 : x
  2. Step 2: Convert to fraction form
    688.80/1,030.08 = 679.12/x
  3. Step 3: Cross multiply
    688.80x = 1,030.08 × 679.12
  4. Step 4: Simplify right side
    688.80x = 699,547.93
  5. Step 5: Solve for x
    x = 699,547.93/688.80
  6. Step 6: Final answer
    x = 1,015.60

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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.