Question

Melissa’s birthday is next week and she has been receiving cards in the mail with different amounts of money. She has received 5 cards with the following amounts: $10, $20, $ 25, $30, $40. If Melissa receives one more card in the mail with $25, which of the following will happen?

Answer 1

Currently, the standard deviation is 10, because on average the cards were $10 away from the mean.

Adding another card with value $25 would decrease the standard deviation because it is closer to the mean the the current standard deviation.