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Finding the Fourth Proportional to 705.51, 973.58 and 390.80

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Solution

The fourth proportional to 705.51, 973.58 and 390.80 is: 539.29

Step by Step Solution

  1. Step 1: Write the proportion equation
    705.51 : 973.58 = 390.80 : x
  2. Step 2: Convert to fraction form
    705.51/973.58 = 390.80/x
  3. Step 3: Cross multiply
    705.51x = 973.58 × 390.80
  4. Step 4: Simplify right side
    705.51x = 380,475.54
  5. Step 5: Solve for x
    x = 380,475.54/705.51
  6. Step 6: Final answer
    x = 539.29

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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.