Home / 465.90-643-279.39

Finding the Fourth Proportional to 465.90, 643 and 279.39

Calculator

Solution

The fourth proportional to 465.90, 643 and 279.39 is: 385.59

Step by Step Solution

  1. Step 1: Write the proportion equation
    465.90 : 643 = 279.39 : x
  2. Step 2: Convert to fraction form
    465.90/643 = 279.39/x
  3. Step 3: Cross multiply
    465.90x = 643 × 279.39
  4. Step 4: Simplify right side
    465.90x = 179,647.77
  5. Step 5: Solve for x
    x = 179,647.77/465.90
  6. Step 6: Final answer
    x = 385.59

Related Problems

Find fourth proportional to 232.95, 321.50 and 139.70
Half scale
Find fourth proportional to 931.80, 1,286 and 558.78
Double scale
Find fourth proportional to 466.90, 644.38 and 280.39
Similar ratio
Find fourth proportional to 698.85, 964.50 and 419.09
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.