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Finding the Fourth Proportional to 680.30, 1,020.45 and 646.70

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Solution

The fourth proportional to 680.30, 1,020.45 and 646.70 is: 970.05

Step by Step Solution

  1. Step 1: Write the proportion equation
    680.30 : 1,020.45 = 646.70 : x
  2. Step 2: Convert to fraction form
    680.30/1,020.45 = 646.70/x
  3. Step 3: Cross multiply
    680.30x = 1,020.45 × 646.70
  4. Step 4: Simplify right side
    680.30x = 659,925.02
  5. Step 5: Solve for x
    x = 659,925.02/680.30
  6. Step 6: Final answer
    x = 970.05

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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.