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Finding the Fourth Proportional to 870.76, 1,201.71 and 661.51

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Solution

The fourth proportional to 870.76, 1,201.71 and 661.51 is: 912.93

Step by Step Solution

  1. Step 1: Write the proportion equation
    870.76 : 1,201.71 = 661.51 : x
  2. Step 2: Convert to fraction form
    870.76/1,201.71 = 661.51/x
  3. Step 3: Cross multiply
    870.76x = 1,201.71 × 661.51
  4. Step 4: Simplify right side
    870.76x = 794,943.18
  5. Step 5: Solve for x
    x = 794,943.18/870.76
  6. Step 6: Final answer
    x = 912.93

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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.