Home / 279.80-418.80-218.60

Finding the Fourth Proportional to 279.80, 418.80 and 218.60

Calculator

Solution

The fourth proportional to 279.80, 418.80 and 218.60 is: 327.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    279.80 : 418.80 = 218.60 : x
  2. Step 2: Convert to fraction form
    279.80/418.80 = 218.60/x
  3. Step 3: Cross multiply
    279.80x = 418.80 × 218.60
  4. Step 4: Simplify right side
    279.80x = 91,549.68
  5. Step 5: Solve for x
    x = 91,549.68/279.80
  6. Step 6: Final answer
    x = 327.20

Related Problems

Find fourth proportional to 139.90, 209.40 and 109.30
Half scale
Find fourth proportional to 559.60, 837.60 and 437.20
Double scale
Find fourth proportional to 280.80, 420.30 and 219.60
Similar ratio
Find fourth proportional to 419.70, 628.20 and 327.90
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.