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Finding the Fourth Proportional to 740.80, 1,022.16 and 642.88

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Solution

The fourth proportional to 740.80, 1,022.16 and 642.88 is: 887.05

Step by Step Solution

  1. Step 1: Write the proportion equation
    740.80 : 1,022.16 = 642.88 : x
  2. Step 2: Convert to fraction form
    740.80/1,022.16 = 642.88/x
  3. Step 3: Cross multiply
    740.80x = 1,022.16 × 642.88
  4. Step 4: Simplify right side
    740.80x = 657,126.22
  5. Step 5: Solve for x
    x = 657,126.22/740.80
  6. Step 6: Final answer
    x = 887.05

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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.