Based on past data, approximately 30% of the oil wells drilled in areas having a certain favorable geological formation have stuck oil. A company has identified 5 locations that posses this information. Assuming that the chance of striking oil on any location is independent of any others, calculate the probability that exactly 2 of the 5 wells strike oil.
@MITer94 ,
@kunkunta This is a fairly standard type of problem, and if you have learned about probability (particularly the binomial distribution), I strongly suggest knowing how to solve these types of problems.
In general, given n events, each of them with probability p occurring independently of each other, the probability that exactly k of these n events occur is:
P(k events occur) = nCk * p^k * (1-p)^(n-k)
where nCk represents “n choose k” or the quantity n!/(n-k)!k!.
Wikipedia gives a decent explanation [url=<a href=“https://en.wikipedia.org/wiki/Binomial_distribution#Probability_mass_function%5Dhere%5B/url”>https://en.wikipedia.org/wiki/Binomial_distribution#Probability_mass_function]here[/url].
In your case, n = 5, k = 2, and p = 0.30.
Another pls. Assume that a bank knows from past experience that between 10 and 11 a.m. Of each day the mean arrival rate is 60 customers per hour. Suppose that the bank wants to determine the
Probability that exactly two customers will arrive in a given minute time minute interval between 10 and 11 a.m. Arrivals are assumed to be constant over a given time interval. Calculate the probability. @MITer94
@kunkunta Fix a 1-minute time interval, say 10:00-10:01 (it could be any 1-minute interval). It is safe to assume that each customer has a p = 1/60 chance of arriving in that 1-minute interval since each interval is equally likely by assumption.
You have 60 customers and you want the probability that exactly 2 show up in your fixed 1-minute interval. Do you see how this relates to your first question?
Is p=1/60, n=60 , and k=2 ?
@kunkunta yeah.
Note that you have to make some assumptions here, such as the assumption that 60 customers/hour arrive between 10-11 am, and that every customer arrives independently of everyone else.
Tnx. The result of an exam score for a given class is normally distributed. If the mean score is 85 points and the standard deviation is equal to
20 points, find the cutoff passing grade such that 83.4% of those taking the test will pass. @MITer94
@kunkunta I can solve, but because this is a fairly straightforward application of the normal distribution, I want you to solve it this time.
Hint: You’ll probably need a graphing calculator.
@MITer94 ,Thank you very much.
@MITer94 would you please solve the question on post #8 ??
@kunkunta 16.6% of the class fail, so find the z-score such that 16.6% of the scores lie to the left of the z-score (you should use a calculator or a lookup table). Once you know the z-score, then you can find the cutoff grade since you know the mean and standard deviation.
- The distribution of annual earnings of all bank tellers with five years of experience is skewed negatively. This distribution has a mean of Birr 15,000 and a standard deviation of Birr 2000. If we draw a random sample of 30 tellers, what is the probability that their earnings will average more than Birr 15,750 annually? Required: Calculate μ and x Calculate Z for X Find the area covered by the interval Interpret the results
- The manager of a hotel has stated that the mean guest bill for a weekend is Birr 400 or less. A member of the hotel’s accounting staff has noticed that the total charges for guest bills have been increasing in recent months. The accountant will use a sample of weekend guest bills to test the manager’s claim. Required: State the null and alternative hypotheses
- A manager wishes to find out whether there is a relationship between the number of radio advertisement aired per week and the amount of sales (in hundreds of Birr) of a product. The data for the sample are given below. Number of Advertisement (X) 2 5 8 8 10 12 Sales (Y) 2 4 7 6 9 10 Compute the value of the correlation coefficient and explain the degree of relationship @MITer94
@kunkunta You are asking questions that are better answered elsewhere, or by using a graphing calculator.
@MITer94 , ok thanks