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Finding the Fourth Proportional to 760.23, 1,139.79 and 390.15

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Solution

The fourth proportional to 760.23, 1,139.79 and 390.15 is: 584.94

Step by Step Solution

  1. Step 1: Write the proportion equation
    760.23 : 1,139.79 = 390.15 : x
  2. Step 2: Convert to fraction form
    760.23/1,139.79 = 390.15/x
  3. Step 3: Cross multiply
    760.23x = 1,139.79 × 390.15
  4. Step 4: Simplify right side
    760.23x = 444,689.07
  5. Step 5: Solve for x
    x = 444,689.07/760.23
  6. Step 6: Final answer
    x = 584.94

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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.