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Finding the Fourth Proportional to 991.47, 1,487.51 and 621.50

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Solution

The fourth proportional to 991.47, 1,487.51 and 621.50 is: 932.45

Step by Step Solution

  1. Step 1: Write the proportion equation
    991.47 : 1,487.51 = 621.50 : x
  2. Step 2: Convert to fraction form
    991.47/1,487.51 = 621.50/x
  3. Step 3: Cross multiply
    991.47x = 1,487.51 × 621.50
  4. Step 4: Simplify right side
    991.47x = 924,486.93
  5. Step 5: Solve for x
    x = 924,486.93/991.47
  6. Step 6: Final answer
    x = 932.45

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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.