Answer:
Step-by-step explanation:
We can use the FOIL method to expand two multiplied binomials. It states that . The FOIL method stands for First(first terms) outer(outer terms) inner(inner terms) last(last terms).
So, we can expand our binomials now!
Answer:
98% Confidencce Interval is ( 3030.6, 7467.4 )
Step-by-step explanation:
Given that:
Sample size 71
Sample size 31
Sample mean 41628
Sample mean 36,379
Population standard deviation = 4934
Population standard deviation 4180
At 98% confidence interval level, the level of significcance = 1 - 0.98 = 0.02
Critical value at
The Margin of Error =
=
=
=
= 2218.40
The Lower limit =
= ( 41628 - 36379 ) - ( 2218.40)
= 5249 - 2218.40
= 3030.6
The upper limit =
= ( 41628 - 36379 ) + ( 2218.40)
= 5249 + 2218.40
= 7467.4
∴ 98% Confidencce Interval is ( 3030.6, 7467.4 )