Search & Filtering
An urn contains ten marbles, of which five are green, two are blue, and three are red. Three marbles are to be drawn from the urn, one at a time without replacement. What is the probability that all three marbles drawn will be green?
A certified public accountant (CPA) has found that nine of ten company audits contain substantial errors. If the CPA audits a series of company accounts, what is the probability that the first account containing substantial errors
(a) Is the third one to be audited?
(b) Will occur on or after the third audited account?
Given that we have already tossed a balanced coin ten times and obtained zero heads, what is the probability that we must toss it at least two more times to obtain the first head?
An oil prospector will drill a succession of holes in a given area to find a productive well. The probability that he is successful on a given trial is .2.
(a) What is the probability that the third hole drilled is the first to yield a productive well?
(b) If the prospector can afford to drill at most ten wells, what is the probability that he will fail to find a productive well?
2. Confidence coefficient or
is expressed as zc.
3. _
is a range of values that is used to estimate a parameter.
4. To compute for the margin of error, use the formula
5. Z& means the
or
6.
is a process of finding the number of elements to be drawn
from a population to create sub-group called sample, subject for a study.
7. The sample size is determined by the equation
8. In the formula/equation for the sample size, n is the required sample size, Za is the
o represents the
and
is the margin
of error.
Ten motors are packaged for sale in a certain warehouse. The motors sell for $100 each, but a double-your-money-back guarantee is in effect for any defectives the purchaser may receive. Find the expected net gain for the seller if the probability of any one motor being defective is .08. (Assume that the quality of any one motor is independent of that of the others.)
A missile protection system consists of n radar sets operating independently, each with a probability of .9 of detecting a missile entering a zone that is covered by all of the units.
(a) If n = 5 and a missile enters the zone, what is the probability that exactly four sets detect the missile? At least one set?
(b) How large must n be if we require that the probability of detecting a missile that enters the zone be .999?
A complex electronic system is built with a certain number of backup components in its subsystems. One subsystem has four identical components, each with a probability of .2 of failing in less than 1000 hours. The subsystem will operate if any two of the four components are operating. Assume that the components operate independently. Find the probability that;
(a) Exactly two of the four components last longer than 1000 hours.
(b) The subsystem operates longer than 1000 hours.
P(x≤4)
A multiple-choice examination has 15 questions, each with five possible answers, only one of which is correct. Suppose that one of the students who takes the examination answers each of the questions with an independent random guess. What is the probability that he answers at least ten questions correctly?
