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Finding the Fourth Proportional to 991.53, 1,368.30 and 543.40

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Solution

The fourth proportional to 991.53, 1,368.30 and 543.40 is: 749.89

Step by Step Solution

  1. Step 1: Write the proportion equation
    991.53 : 1,368.30 = 543.40 : x
  2. Step 2: Convert to fraction form
    991.53/1,368.30 = 543.40/x
  3. Step 3: Cross multiply
    991.53x = 1,368.30 × 543.40
  4. Step 4: Simplify right side
    991.53x = 743,537.64
  5. Step 5: Solve for x
    x = 743,537.64/991.53
  6. Step 6: Final answer
    x = 749.89

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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.