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Finding the Fourth Proportional to 859.38, 1,289.40 and 339.63

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Solution

The fourth proportional to 859.38, 1,289.40 and 339.63 is: 509.58

Step by Step Solution

  1. Step 1: Write the proportion equation
    859.38 : 1,289.40 = 339.63 : x
  2. Step 2: Convert to fraction form
    859.38/1,289.40 = 339.63/x
  3. Step 3: Cross multiply
    859.38x = 1,289.40 × 339.63
  4. Step 4: Simplify right side
    859.38x = 437,918.92
  5. Step 5: Solve for x
    x = 437,918.92/859.38
  6. Step 6: Final answer
    x = 509.58

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Double scale
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1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.