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Finding the Fourth Proportional to 972, 1,340.96 and 640.58

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Solution

The fourth proportional to 972, 1,340.96 and 640.58 is: 883.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    972 : 1,340.96 = 640.58 : x
  2. Step 2: Convert to fraction form
    972/1,340.96 = 640.58/x
  3. Step 3: Cross multiply
    972x = 1,340.96 × 640.58
  4. Step 4: Simplify right side
    972x = 858,992.16
  5. Step 5: Solve for x
    x = 858,992.16/972
  6. Step 6: Final answer
    x = 883.74

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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.