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Finding the Fourth Proportional to 838.95, 1,158.21 and 642.84

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Solution

The fourth proportional to 838.95, 1,158.21 and 642.84 is: 887.47

Step by Step Solution

  1. Step 1: Write the proportion equation
    838.95 : 1,158.21 = 642.84 : x
  2. Step 2: Convert to fraction form
    838.95/1,158.21 = 642.84/x
  3. Step 3: Cross multiply
    838.95x = 1,158.21 × 642.84
  4. Step 4: Simplify right side
    838.95x = 744,543.72
  5. Step 5: Solve for x
    x = 744,543.72/838.95
  6. Step 6: Final answer
    x = 887.47

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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.