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Finding the Fourth Proportional to 780.57, 1,170.42 and 260.30

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Solution

The fourth proportional to 780.57, 1,170.42 and 260.30 is: 390.30

Step by Step Solution

  1. Step 1: Write the proportion equation
    780.57 : 1,170.42 = 260.30 : x
  2. Step 2: Convert to fraction form
    780.57/1,170.42 = 260.30/x
  3. Step 3: Cross multiply
    780.57x = 1,170.42 × 260.30
  4. Step 4: Simplify right side
    780.57x = 304,655.69
  5. Step 5: Solve for x
    x = 304,655.69/780.57
  6. Step 6: Final answer
    x = 390.30

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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.