Home / 393.45-542.98-218.80

Finding the Fourth Proportional to 393.45, 542.98 and 218.80

Calculator

Solution

The fourth proportional to 393.45, 542.98 and 218.80 is: 301.95

Step by Step Solution

  1. Step 1: Write the proportion equation
    393.45 : 542.98 = 218.80 : x
  2. Step 2: Convert to fraction form
    393.45/542.98 = 218.80/x
  3. Step 3: Cross multiply
    393.45x = 542.98 × 218.80
  4. Step 4: Simplify right side
    393.45x = 118,801.31
  5. Step 5: Solve for x
    x = 118,801.31/393.45
  6. Step 6: Final answer
    x = 301.95

Related Problems

Find fourth proportional to 196.73, 271.49 and 109.40
Half scale
Find fourth proportional to 786.90, 1,085.96 and 437.59
Double scale
Find fourth proportional to 394.45, 544.36 and 219.80
Similar ratio
Find fourth proportional to 590.18, 814.47 and 328.19
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.