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Finding the Fourth Proportional to 971, 1,339.31 and 621.53

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Solution

The fourth proportional to 971, 1,339.31 and 621.53 is: 857.28

Step by Step Solution

  1. Step 1: Write the proportion equation
    971 : 1,339.31 = 621.53 : x
  2. Step 2: Convert to fraction form
    971/1,339.31 = 621.53/x
  3. Step 3: Cross multiply
    971x = 1,339.31 × 621.53
  4. Step 4: Simplify right side
    971x = 832,421.34
  5. Step 5: Solve for x
    x = 832,421.34/971
  6. Step 6: Final answer
    x = 857.28

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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.