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Finding the Fourth Proportional to 714.36, 985.78 and 399.57

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Solution

The fourth proportional to 714.36, 985.78 and 399.57 is: 551.38

Step by Step Solution

  1. Step 1: Write the proportion equation
    714.36 : 985.78 = 399.57 : x
  2. Step 2: Convert to fraction form
    714.36/985.78 = 399.57/x
  3. Step 3: Cross multiply
    714.36x = 985.78 × 399.57
  4. Step 4: Simplify right side
    714.36x = 393,888.58
  5. Step 5: Solve for x
    x = 393,888.58/714.36
  6. Step 6: Final answer
    x = 551.38

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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.