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Finding the Fourth Proportional to 685.21, 945.12 and 422.77

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Solution

The fourth proportional to 685.21, 945.12 and 422.77 is: 583.13

Step by Step Solution

  1. Step 1: Write the proportion equation
    685.21 : 945.12 = 422.77 : x
  2. Step 2: Convert to fraction form
    685.21/945.12 = 422.77/x
  3. Step 3: Cross multiply
    685.21x = 945.12 × 422.77
  4. Step 4: Simplify right side
    685.21x = 399,568.38
  5. Step 5: Solve for x
    x = 399,568.38/685.21
  6. Step 6: Final answer
    x = 583.13

Related Problems

Find fourth proportional to 342.61, 472.56 and 211.39
Half scale
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Double scale
Find fourth proportional to 686.21, 946.50 and 423.77
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.