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Finding the Fourth Proportional to 985.31, 1,478.65 and 637.79

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Solution

The fourth proportional to 985.31, 1,478.65 and 637.79 is: 957.12

Step by Step Solution

  1. Step 1: Write the proportion equation
    985.31 : 1,478.65 = 637.79 : x
  2. Step 2: Convert to fraction form
    985.31/1,478.65 = 637.79/x
  3. Step 3: Cross multiply
    985.31x = 1,478.65 × 637.79
  4. Step 4: Simplify right side
    985.31x = 943,060.79
  5. Step 5: Solve for x
    x = 943,060.79/985.31
  6. Step 6: Final answer
    x = 957.12

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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.