the denominator would be 12
Answer:
90% CI expects to capture u 90% of time
(a) This means 0.9 * 1000 = 900 intervals will capture u
(b) Here we treat CI as binomial random variable, having probability 0.9 for success
n = 1000
p = 0.9
For this case, applying normal approximation to binomial, we get:
mean = n*p= 900
variance = n*p*(1-p) = 90
std dev = 9.4868
We want to Find : P(890 <= X <= 910) = P( 889.5 < X < 910.5) (integer continuity correction)
We convert to standard normal form, Z ~ N(0,1) by z1 = (x1 - u )/s
so z1 = (889.5 - 900 )/9.4868 = -1.11
so z2 = (910.5 - 900 )/9.4868 = 1.11
P( 889.5 < X < 910.5) = P(z1 < Z < z2) = P( Z < 1.11) - P(Z < -1.11)
= 0.8665 - 0.1335
= 0.733
Add every thing and u. Get 10.10 7x2 then 14. Then add 10 so u basically just in total get 14.10
1.50 pounds.
(dont have pound symbol, only $)
