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Finding the Fourth Proportional to 785.67, 1,085.12 and 491.19

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Solution

The fourth proportional to 785.67, 1,085.12 and 491.19 is: 678.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    785.67 : 1,085.12 = 491.19 : x
  2. Step 2: Convert to fraction form
    785.67/1,085.12 = 491.19/x
  3. Step 3: Cross multiply
    785.67x = 1,085.12 × 491.19
  4. Step 4: Simplify right side
    785.67x = 532,997.64
  5. Step 5: Solve for x
    x = 532,997.64/785.67
  6. Step 6: Final answer
    x = 678.40

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Half scale
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Double scale
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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.