7. Construct 90% confidence intervals to estimate the difference

between population means and proportions for the following provided data:

[10 Marks]

a)

b)

Sample 1

x₁ = 65

$²=9

m₁ = 19

i) Assume 0₁

0₂

ii) Assume 0₁ = 0₂

Sample 1

x₂ =

150

n₁ = 300

Sample 2

x₂ = 55

s² = 12

n₂ = 25

Sample 2

x2

=

100

n₂ = 400