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Finding the Fourth Proportional to 998.17, 1,376.23 and 643.51

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Solution

The fourth proportional to 998.17, 1,376.23 and 643.51 is: 887.24

Step by Step Solution

  1. Step 1: Write the proportion equation
    998.17 : 1,376.23 = 643.51 : x
  2. Step 2: Convert to fraction form
    998.17/1,376.23 = 643.51/x
  3. Step 3: Cross multiply
    998.17x = 1,376.23 × 643.51
  4. Step 4: Simplify right side
    998.17x = 885,617.77
  5. Step 5: Solve for x
    x = 885,617.77/998.17
  6. Step 6: Final answer
    x = 887.24

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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.