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Finding the Fourth Proportional to 647.90, 972 and 339.59

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Solution

The fourth proportional to 647.90, 972 and 339.59 is: 509.47

Step by Step Solution

  1. Step 1: Write the proportion equation
    647.90 : 972 = 339.59 : x
  2. Step 2: Convert to fraction form
    647.90/972 = 339.59/x
  3. Step 3: Cross multiply
    647.90x = 972 × 339.59
  4. Step 4: Simplify right side
    647.90x = 330,083.91
  5. Step 5: Solve for x
    x = 330,083.91/647.90
  6. Step 6: Final answer
    x = 509.47

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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.