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Finding the Fourth Proportional to 689.15, 950.94 and 390.39

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Solution

The fourth proportional to 689.15, 950.94 and 390.39 is: 538.69

Step by Step Solution

  1. Step 1: Write the proportion equation
    689.15 : 950.94 = 390.39 : x
  2. Step 2: Convert to fraction form
    689.15/950.94 = 390.39/x
  3. Step 3: Cross multiply
    689.15x = 950.94 × 390.39
  4. Step 4: Simplify right side
    689.15x = 371,237.47
  5. Step 5: Solve for x
    x = 371,237.47/689.15
  6. Step 6: Final answer
    x = 538.69

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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.