Home / 157.40-217.71-128.96

Finding the Fourth Proportional to 157.40, 217.71 and 128.96

Calculator

Solution

The fourth proportional to 157.40, 217.71 and 128.96 is: 178.37

Step by Step Solution

  1. Step 1: Write the proportion equation
    157.40 : 217.71 = 128.96 : x
  2. Step 2: Convert to fraction form
    157.40/217.71 = 128.96/x
  3. Step 3: Cross multiply
    157.40x = 217.71 × 128.96
  4. Step 4: Simplify right side
    157.40x = 28,075.88
  5. Step 5: Solve for x
    x = 28,075.88/157.40
  6. Step 6: Final answer
    x = 178.37

Related Problems

Find fourth proportional to 78.70, 108.86 and 64.48
Half scale
Find fourth proportional to 314.80, 435.42 and 257.92
Double scale
Find fourth proportional to 158.40, 219.09 and 129.96
Similar ratio
Find fourth proportional to 236.10, 326.57 and 193.44
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.