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Finding the Fourth Proportional to 661.40, 990.68 and 539.08

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Solution

The fourth proportional to 661.40, 990.68 and 539.08 is: 807.46

Step by Step Solution

  1. Step 1: Write the proportion equation
    661.40 : 990.68 = 539.08 : x
  2. Step 2: Convert to fraction form
    661.40/990.68 = 539.08/x
  3. Step 3: Cross multiply
    661.40x = 990.68 × 539.08
  4. Step 4: Simplify right side
    661.40x = 534,055.77
  5. Step 5: Solve for x
    x = 534,055.77/661.40
  6. Step 6: Final answer
    x = 807.46

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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.