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Finding the Fourth Proportional to 705.21, 973.20 and 390.45

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Solution

The fourth proportional to 705.21, 973.20 and 390.45 is: 538.83

Step by Step Solution

  1. Step 1: Write the proportion equation
    705.21 : 973.20 = 390.45 : x
  2. Step 2: Convert to fraction form
    705.21/973.20 = 390.45/x
  3. Step 3: Cross multiply
    705.21x = 973.20 × 390.45
  4. Step 4: Simplify right side
    705.21x = 379,985.94
  5. Step 5: Solve for x
    x = 379,985.94/705.21
  6. Step 6: Final answer
    x = 538.83

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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.