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Finding the Fourth Proportional to 386.76, 578.08 and 317.90

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Solution

The fourth proportional to 386.76, 578.08 and 317.90 is: 475.16

Step by Step Solution

  1. Step 1: Write the proportion equation
    386.76 : 578.08 = 317.90 : x
  2. Step 2: Convert to fraction form
    386.76/578.08 = 317.90/x
  3. Step 3: Cross multiply
    386.76x = 578.08 × 317.90
  4. Step 4: Simplify right side
    386.76x = 183,771.63
  5. Step 5: Solve for x
    x = 183,771.63/386.76
  6. Step 6: Final answer
    x = 475.16

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.