Home / 902.89-1,248.11-643.15

Finding the Fourth Proportional to 902.89, 1,248.11 and 643.15

Calculator

Solution

The fourth proportional to 902.89, 1,248.11 and 643.15 is: 889.06

Step by Step Solution

  1. Step 1: Write the proportion equation
    902.89 : 1,248.11 = 643.15 : x
  2. Step 2: Convert to fraction form
    902.89/1,248.11 = 643.15/x
  3. Step 3: Cross multiply
    902.89x = 1,248.11 × 643.15
  4. Step 4: Simplify right side
    902.89x = 802,721.95
  5. Step 5: Solve for x
    x = 802,721.95/902.89
  6. Step 6: Final answer
    x = 889.06

Related Problems

Find fourth proportional to 451.45, 624.06 and 321.58
Half scale
Find fourth proportional to 1,805.78, 2,496.22 and 1,286.30
Double scale
Find fourth proportional to 903.89, 1,249.49 and 644.15
Similar ratio
Find fourth proportional to 1,354.34, 1,872.17 and 964.73
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.