After surveying 100 parents, researchers concluded that 90 percent of babies can walk by the age of 10 months. Why is this an inappropriate conclusion?

The conclusion drawn is inappropriate because the data collection is unreliable and the method used for collection is wrong.

Explanation:

The use of wrong methods for the collection of data for such studies and then drawing conclusions out of them is one of the causes for the study to be said to be unreliable completely.

There is no way to reliably conclude the age at which the children start to walk by talking to the parents as parents do not qualify or take time data of the time children start walking.

The parents are unreliable sources here no matter how big the sample size is and only the researchers themselves could notice and get the reliable results required in this case.