Answer:
0.4166
Step-by-step explanation:
Given that we have a factory that produces light bulbs and that each bulb independently has a 5% probability of dying after 4 years.
i.e. prob = 0.05 for each bulb for dying since independent is given
Also there are only two outcomes either working or dying.
X no of bulbs still working is binomial with
constant probability p = 0.95, q = 0.05 and n = 1250
np =
nq = 62.5
Both are >5. Hence X can be approximated to normal with
mean = 1187.5 and variance =npq = 59.375
std dev = 7.7055
Using central limit theorem we find that X is N(1187.8, 7.7055)
P(X > 1200)
=
Answer:
in this tiangle tanA = 8/15
Theorem: If two secant segments are drawn to a circle from an external point, then the products of the lengths of each secant with its external segment are equal.
In your case this theorem looks as
Answer: true always.