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Finding the Fourth Proportional to 620.79, 931.55 and 255.51

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Solution

The fourth proportional to 620.79, 931.55 and 255.51 is: 383.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    620.79 : 931.55 = 255.51 : x
  2. Step 2: Convert to fraction form
    620.79/931.55 = 255.51/x
  3. Step 3: Cross multiply
    620.79x = 931.55 × 255.51
  4. Step 4: Simplify right side
    620.79x = 238,020.34
  5. Step 5: Solve for x
    x = 238,020.34/620.79
  6. Step 6: Final answer
    x = 383.42

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Double scale
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Similar ratio
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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.