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Finding the Fourth Proportional to 691.84, 955.38 and 642.70

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Solution

The fourth proportional to 691.84, 955.38 and 642.70 is: 887.52

Step by Step Solution

  1. Step 1: Write the proportion equation
    691.84 : 955.38 = 642.70 : x
  2. Step 2: Convert to fraction form
    691.84/955.38 = 642.70/x
  3. Step 3: Cross multiply
    691.84x = 955.38 × 642.70
  4. Step 4: Simplify right side
    691.84x = 614,022.73
  5. Step 5: Solve for x
    x = 614,022.73/691.84
  6. Step 6: Final answer
    x = 887.52

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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.