Question

There is an advertisement on television that says if used at the first sign of a cold sore; it will be healed in 2.5 days.  If you look at the small print under the ad, is says, the median healing time is 4.1 days and 25% of the cold sores were healed in 2.5 days.

Think about this:

Why did they use the median healing time instead of the mean?

With only 25% of cold sores healed in the advertised time, would you buy this produce expecting to see your cold sore healed in 2.5 days?

Answer 1

For the first query it is given that median is 4.1days instead of mean. Because there may exists a few cases which takes a lot of time to heal, known as outlier. Mean is widely affected by outlier. This is why here median is mentioned over mean.

Here only 25% cold sore recovers in 2.5 day and rest of 75% takes a lot of time. And as mentioned in previous paragraph their may exist some outliers. Therefore expected time for healing the cold sore will be more than 2.5days.