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Finding the Fourth Proportional to 786.16, 1,085.52 and 638.56

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Solution

The fourth proportional to 786.16, 1,085.52 and 638.56 is: 881.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    786.16 : 1,085.52 = 638.56 : x
  2. Step 2: Convert to fraction form
    786.16/1,085.52 = 638.56/x
  3. Step 3: Cross multiply
    786.16x = 1,085.52 × 638.56
  4. Step 4: Simplify right side
    786.16x = 693,169.65
  5. Step 5: Solve for x
    x = 693,169.65/786.16
  6. Step 6: Final answer
    x = 881.72

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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.