ch6sometechniquesofcalculation-2.studentview

# 1 2 1 x n1 4 yi 1203 2

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Unformatted text preview: 2: N 2 = 5, µ 2 = 24, σ 2 = 4 µ1 ∑x = N1 i ⇔ ∑ xi = N1 ⋅ µ1 = 4 ×15 µ2 ∑y = N2 i ⇔ ∑ yi = N 2 ⋅ µ 2 = 5 × 24 ∴ ∑ xi = 60...............(1) σ 2 1 ∑x = N1 4 ∴ ∑ yi = 120...................(3) 2 i −µ 2 1 σ 3 2 2 ∑y = N2 5 2 i 2 − µ2 42 = ∑ xi2 − 152 2 ∑y = 2 i 2 i − 24 2 ∴ ∑ xi2 = 964.............(2) 4 ∑ xi2 = 4(16 + 152 ) ∑ xi2 = 16 + 152 ∴ ∑ yi2 = 2925.............(4) 5 ∑ yi2 = 5(9 + 242 ) ∑y = 9 + 24 2 Now let’s combine the two data sets……… Now µ =∑i Z z N Z =N1 +N 2 =9, µ =?, σ =? Z Z NZ 9 ∴ Z =20.......(5) µ µ Z x ∑ = z ∑ = NZ i +∑ i y 60 + 120 = =20 9 σ2 Z σ2 Z 2 i 2...
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## This note was uploaded on 04/22/2011 for the course STAT 301 taught by Professor Gabrille during the Spring '11 term at HKU.

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