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Finding the Fourth Proportional to 991.02, 1,487.36 and 342.21

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Solution

The fourth proportional to 991.02, 1,487.36 and 342.21 is: 513.60

Step by Step Solution

  1. Step 1: Write the proportion equation
    991.02 : 1,487.36 = 342.21 : x
  2. Step 2: Convert to fraction form
    991.02/1,487.36 = 342.21/x
  3. Step 3: Cross multiply
    991.02x = 1,487.36 × 342.21
  4. Step 4: Simplify right side
    991.02x = 508,989.47
  5. Step 5: Solve for x
    x = 508,989.47/991.02
  6. Step 6: Final answer
    x = 513.60

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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.