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Finding the Fourth Proportional to 991.45, 1,368.21 and 549.39

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Solution

The fourth proportional to 991.45, 1,368.21 and 549.39 is: 758.16

Step by Step Solution

  1. Step 1: Write the proportion equation
    991.45 : 1,368.21 = 549.39 : x
  2. Step 2: Convert to fraction form
    991.45/1,368.21 = 549.39/x
  3. Step 3: Cross multiply
    991.45x = 1,368.21 × 549.39
  4. Step 4: Simplify right side
    991.45x = 751,680.89
  5. Step 5: Solve for x
    x = 751,680.89/991.45
  6. Step 6: Final answer
    x = 758.16

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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.