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Finding the Fourth Proportional to 1,285.72, 1,775.34 and 788.68

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Solution

The fourth proportional to 1,285.72, 1,775.34 and 788.68 is: 1,089.02

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,285.72 : 1,775.34 = 788.68 : x
  2. Step 2: Convert to fraction form
    1,285.72/1,775.34 = 788.68/x
  3. Step 3: Cross multiply
    1,285.72x = 1,775.34 × 788.68
  4. Step 4: Simplify right side
    1,285.72x = 1,400,170.71
  5. Step 5: Solve for x
    x = 1,400,170.71/1,285.72
  6. Step 6: Final answer
    x = 1,089.02

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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.