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Finding the Fourth Proportional to 859.78, 1,186.45 and 486.75

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Solution

The fourth proportional to 859.78, 1,186.45 and 486.75 is: 671.69

Step by Step Solution

  1. Step 1: Write the proportion equation
    859.78 : 1,186.45 = 486.75 : x
  2. Step 2: Convert to fraction form
    859.78/1,186.45 = 486.75/x
  3. Step 3: Cross multiply
    859.78x = 1,186.45 × 486.75
  4. Step 4: Simplify right side
    859.78x = 577,504.54
  5. Step 5: Solve for x
    x = 577,504.54/859.78
  6. Step 6: Final answer
    x = 671.69

Related Problems

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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.