Home / 279.21-385.66-209.60

Finding the Fourth Proportional to 279.21, 385.66 and 209.60

Calculator

Solution

The fourth proportional to 279.21, 385.66 and 209.60 is: 289.51

Step by Step Solution

  1. Step 1: Write the proportion equation
    279.21 : 385.66 = 209.60 : x
  2. Step 2: Convert to fraction form
    279.21/385.66 = 209.60/x
  3. Step 3: Cross multiply
    279.21x = 385.66 × 209.60
  4. Step 4: Simplify right side
    279.21x = 80,834.34
  5. Step 5: Solve for x
    x = 80,834.34/279.21
  6. Step 6: Final answer
    x = 289.51

Related Problems

Find fourth proportional to 139.61, 192.83 and 104.80
Half scale
Find fourth proportional to 558.42, 771.32 and 419.20
Double scale
Find fourth proportional to 280.21, 387.04 and 210.60
Similar ratio
Find fourth proportional to 418.82, 578.49 and 314.40
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.