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Finding the Fourth Proportional to 977.60, 1,347.84 and 645.50

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Solution

The fourth proportional to 977.60, 1,347.84 and 645.50 is: 889.97

Step by Step Solution

  1. Step 1: Write the proportion equation
    977.60 : 1,347.84 = 645.50 : x
  2. Step 2: Convert to fraction form
    977.60/1,347.84 = 645.50/x
  3. Step 3: Cross multiply
    977.60x = 1,347.84 × 645.50
  4. Step 4: Simplify right side
    977.60x = 870,030.72
  5. Step 5: Solve for x
    x = 870,030.72/977.60
  6. Step 6: Final answer
    x = 889.97

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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.