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Finding the Fourth Proportional to 647.79, 894.42 and 399.45

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Solution

The fourth proportional to 647.79, 894.42 and 399.45 is: 551.53

Step by Step Solution

  1. Step 1: Write the proportion equation
    647.79 : 894.42 = 399.45 : x
  2. Step 2: Convert to fraction form
    647.79/894.42 = 399.45/x
  3. Step 3: Cross multiply
    647.79x = 894.42 × 399.45
  4. Step 4: Simplify right side
    647.79x = 357,276.07
  5. Step 5: Solve for x
    x = 357,276.07/647.79
  6. Step 6: Final answer
    x = 551.53

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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.