Home / 165.21-247.69-78.49

Finding the Fourth Proportional to 165.21, 247.69 and 78.49

Calculator

Solution

The fourth proportional to 165.21, 247.69 and 78.49 is: 117.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    165.21 : 247.69 = 78.49 : x
  2. Step 2: Convert to fraction form
    165.21/247.69 = 78.49/x
  3. Step 3: Cross multiply
    165.21x = 247.69 × 78.49
  4. Step 4: Simplify right side
    165.21x = 19,441.19
  5. Step 5: Solve for x
    x = 19,441.19/165.21
  6. Step 6: Final answer
    x = 117.68

Related Problems

Find fourth proportional to 82.61, 123.85 and 39.25
Half scale
Find fourth proportional to 330.42, 495.38 and 156.98
Double scale
Find fourth proportional to 166.21, 249.19 and 79.49
Similar ratio
Find fourth proportional to 247.82, 371.54 and 117.74
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.