Which of the statement are true ?
The product of means in a proportion is 60. If one of the extermes is 4, then the other is 20.

Answer

To determine whether the statement is true, we can use the concept of proportions and the relationship between the means and extremes.

### Step-by-Step Solution:

1. **Understanding the Proportion**:
In a proportion, we have two ratios, say \( \frac{a}{b} = \frac{c}{d} \). Here, \( a \) and \( d \) are the extremes, while \( b \) and \( c \) are the means.

2. **Given Information**:
We are given that the product of the means is 60. This means:
\[ b \cdot c = 60 \]
We also know that one of the extremes \( a = 4 \) and we need to find the other extreme \( d \).

3. **Using the Relationship of Extremes**:
The product of the extremes is equal to the product of the means:
\[ a \cdot d = b \cdot c \]
Substituting the known values:
\[ 4 \cdot d = 60 \]

4. **Solving for \( d \)**:
To find \( d \), we can rearrange the equation:
\[ d = \frac{60}{4} \]
Simplifying this gives:
\[ d = 15 \]

5. **Conclusion**:
The other extreme \( d \) is 15, not 20. Therefore, the statement "if one of the extremes is 4, then the other is 20" is **false**.

### Summary of the Steps:
- Identify the relationship between means and extremes in a proportion.
- Use the given product of means to set up an equation.
- Solve for the unknown extreme.