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Finding the Fourth Proportional to 974.76, 1,345.02 and 643.32

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Solution

The fourth proportional to 974.76, 1,345.02 and 643.32 is: 887.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    974.76 : 1,345.02 = 643.32 : x
  2. Step 2: Convert to fraction form
    974.76/1,345.02 = 643.32/x
  3. Step 3: Cross multiply
    974.76x = 1,345.02 × 643.32
  4. Step 4: Simplify right side
    974.76x = 865,278.27
  5. Step 5: Solve for x
    x = 865,278.27/974.76
  6. Step 6: Final answer
    x = 887.68

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Double scale
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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.