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Finding the Fourth Proportional to 172.10, 256.78 and 145.10

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Solution

The fourth proportional to 172.10, 256.78 and 145.10 is: 216.49

Step by Step Solution

  1. Step 1: Write the proportion equation
    172.10 : 256.78 = 145.10 : x
  2. Step 2: Convert to fraction form
    172.10/256.78 = 145.10/x
  3. Step 3: Cross multiply
    172.10x = 256.78 × 145.10
  4. Step 4: Simplify right side
    172.10x = 37,258.78
  5. Step 5: Solve for x
    x = 37,258.78/172.10
  6. Step 6: Final answer
    x = 216.49

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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.