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Finding the Fourth Proportional to 653, 978.80 and 287.72

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Solution

The fourth proportional to 653, 978.80 and 287.72 is: 431.27

Step by Step Solution

  1. Step 1: Write the proportion equation
    653 : 978.80 = 287.72 : x
  2. Step 2: Convert to fraction form
    653/978.80 = 287.72/x
  3. Step 3: Cross multiply
    653x = 978.80 × 287.72
  4. Step 4: Simplify right side
    653x = 281,620.34
  5. Step 5: Solve for x
    x = 281,620.34/653
  6. Step 6: Final answer
    x = 431.27

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