1. EXAMPLE 1 Finding a Mean Biology A marine biologist records the following locations of 6 deep sea jellyfish in relation to the ocean surface: –2278 feet, –1875 feet, –3210 feet, –2755 feet, –2407 feet, and –2901 feet. What is the mean location of the deep sea jellies? Mean = –2278 + (–1875) + (–3210) + (–2755) + (–2407) + (–2901) 6 = –15,426 6 = –2571 ANSWER The mean location in relation to the ocean surface is –2571 feet.

2. GUIDED PRACTICE for Example 1 Find the mean of the data. 1. –3 o C, 44 o C, –11 o C, 9 o C, –21 o C Mean = –3 + 44 + (–11 ) + 9 + (–21 ) 5 = 18 5 = 3.6 o C.

3. GUIDED PRACTICE for Example 1 Find the mean of the data. in, in, in, in 2. 12 1 2 14 3 4 20 1 2 16 3 4 Mean = 12 + 14 + 20 + 16 4 1 2 1 2 3 4 3 4 = 1 8 in. 16