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Finding the Fourth Proportional to 681.60, 986.40 and 681.60

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Solution

The fourth proportional to 681.60, 986.40 and 681.60 is: 986.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    681.60 : 986.40 = 681.60 : x
  2. Step 2: Convert to fraction form
    681.60/986.40 = 681.60/x
  3. Step 3: Cross multiply
    681.60x = 986.40 × 681.60
  4. Step 4: Simplify right side
    681.60x = 672,330.24
  5. Step 5: Solve for x
    x = 672,330.24/681.60
  6. Step 6: Final answer
    x = 986.40

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1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.45) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.