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Finding the Fourth Proportional to 1,319.75, 1,979.48 and 345.72

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Solution

The fourth proportional to 1,319.75, 1,979.48 and 345.72 is: 518.54

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,319.75 : 1,979.48 = 345.72 : x
  2. Step 2: Convert to fraction form
    1,319.75/1,979.48 = 345.72/x
  3. Step 3: Cross multiply
    1,319.75x = 1,979.48 × 345.72
  4. Step 4: Simplify right side
    1,319.75x = 684,345.83
  5. Step 5: Solve for x
    x = 684,345.83/1,319.75
  6. Step 6: Final answer
    x = 518.54

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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.