Question

Hi guys..
Find mean if ;
a=20, fidi=-10, fi=3


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Answer 1

Hope you will understand

Answer 2

Answer:

An ecosystem is a geographic area where plants, animals, and other organisms, as well as weather and landscape, work together to form a bubble of life. Ecosystems contain biotic or living, parts, as well as abiotic factors, or nonliving parts. ... Ecosystems can be very large or very small.