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Finding the Fourth Proportional to 870.35, 1,200.38 and 765.21

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Solution

The fourth proportional to 870.35, 1,200.38 and 765.21 is: 1,055.37

Step by Step Solution

  1. Step 1: Write the proportion equation
    870.35 : 1,200.38 = 765.21 : x
  2. Step 2: Convert to fraction form
    870.35/1,200.38 = 765.21/x
  3. Step 3: Cross multiply
    870.35x = 1,200.38 × 765.21
  4. Step 4: Simplify right side
    870.35x = 918,534.45
  5. Step 5: Solve for x
    x = 918,534.45/870.35
  6. Step 6: Final answer
    x = 1,055.37

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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.