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Finding the Fourth Proportional to 312.88, 431.36 and 302.80

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Solution

The fourth proportional to 312.88, 431.36 and 302.80 is: 417.46

Step by Step Solution

  1. Step 1: Write the proportion equation
    312.88 : 431.36 = 302.80 : x
  2. Step 2: Convert to fraction form
    312.88/431.36 = 302.80/x
  3. Step 3: Cross multiply
    312.88x = 431.36 × 302.80
  4. Step 4: Simplify right side
    312.88x = 130,615.81
  5. Step 5: Solve for x
    x = 130,615.81/312.88
  6. Step 6: Final answer
    x = 417.46

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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.