Answer: Symmetric
Step-by-step explanation:
The majority of children start walking at one and a half years so when the distribution is plotted on a histogram, it will be symmetric and unimodal. This means that it will have a single peak that is approximately 18 months.
This kind of distribution is a normal distribution and will have a shape similar to the one in the above diagram. This contrasts another type of distribution, the uniform distribution, when any value is possible, such as plotting the value of a card drawn from a complete deck.