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Finding the Fourth Proportional to 621.39, 857.27 and 385.18

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Solution

The fourth proportional to 621.39, 857.27 and 385.18 is: 531.39

Step by Step Solution

  1. Step 1: Write the proportion equation
    621.39 : 857.27 = 385.18 : x
  2. Step 2: Convert to fraction form
    621.39/857.27 = 385.18/x
  3. Step 3: Cross multiply
    621.39x = 857.27 × 385.18
  4. Step 4: Simplify right side
    621.39x = 330,199.19
  5. Step 5: Solve for x
    x = 330,199.19/621.39
  6. Step 6: Final answer
    x = 531.39

Related Problems

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Half scale
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Double scale
Find fourth proportional to 622.39, 858.64 and 386.18
Similar ratio
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1.5x scale

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.