Alice recorded the outside temperature at noon each day for one week. These were the results.

Monday: 78

Tuesday: 85

Wednesday: 82

Thursday: 84

Friday: 82

Saturday: 79

Sunday: 80

What is the standard deviation of the temperatures?

A bird watcher observed how many birds came to her bird feeder for four days. These were the results:

Day 1: 15

Day 2: 12

Day 3: 10

Day 4: 13

Which answer is closest to the standard deviation of the number of birds to visit the bird feeder over the four days?