What is the volume of toothpaste in a tube ?

d. normal if the population is normally distributed

Step-by-step explanation:

Central Limit Theorem

The Central Limit Theorem establishes that, for a normally distributed random variable X, with mean and standard deviation , the sampling distribution of the sample means with size n can be approximated to a normal distribution with mean and standard deviation .

For a skewed variable, the Central Limit Theorem can also be applied, as long as n is at least 30.

In this question:

Sample size less than 30, so only will be normal if the population is normally distribution, and thus the correct answer is given by option d.