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Finding the Fourth Proportional to 689.25, 948.38 and 665.31

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Solution

The fourth proportional to 689.25, 948.38 and 665.31 is: 915.43

Step by Step Solution

  1. Step 1: Write the proportion equation
    689.25 : 948.38 = 665.31 : x
  2. Step 2: Convert to fraction form
    689.25/948.38 = 665.31/x
  3. Step 3: Cross multiply
    689.25x = 948.38 × 665.31
  4. Step 4: Simplify right side
    689.25x = 630,963.37
  5. Step 5: Solve for x
    x = 630,963.37/689.25
  6. Step 6: Final answer
    x = 915.43

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1.5x scale

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.