Answer: 2.5
Step-by-step explanation:
Mean m = Sum s ÷ no of observation n
m = 2.5, n = 10
2.5 = s ÷ 10
s = 10 × 2.5
s = 25.
If one observation 2.5 is deleted from sum 25, new sum equals 25 — 2.5 = 22.5.
The no of observation becomes 9.
Therefore new mean = 22.5 ÷ 9
m = 2.5.
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