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Finding the Fourth Proportional to 780.32, 1,075.87 and 500.09

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Solution

The fourth proportional to 780.32, 1,075.87 and 500.09 is: 689.50

Step by Step Solution

  1. Step 1: Write the proportion equation
    780.32 : 1,075.87 = 500.09 : x
  2. Step 2: Convert to fraction form
    780.32/1,075.87 = 500.09/x
  3. Step 3: Cross multiply
    780.32x = 1,075.87 × 500.09
  4. Step 4: Simplify right side
    780.32x = 538,029.33
  5. Step 5: Solve for x
    x = 538,029.33/780.32
  6. Step 6: Final answer
    x = 689.50

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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.