Solution:
Given:
p = probability of an event A = 0.4
c = confidence level = 0.9 that is: 90%
E = margin of Error = 0.1
We have to find number of trials , that is sample size n.
Formula:
Zc is z critical value for c = 90% confidence level.
Find Area = ( 1 + c ) / 2 = ( 1 + 0.90) / 2 = 1.90 / 2 = 0.9500
Look in z table for Area = 0.9500 or its closest area and find corresponding z value.
Area 0.9500 is in between 0.9495 and 0.9505 and both the area are at same distance from 0.9500
Thus we look for both area and find both z values
Thus Area 0.9495 corresponds to 1.64 and 0.9505 corresponds to 1.65
Thus average of both z values is : ( 1.64+1.65) / 2 = 1.645
Thus Zc = 1.645
Thus
Thus required number of trials are: 65
Ans. P 0.97. 12. Suppose an event A has probability suppose an event A has probability 0.4. How many trials must be...
Consider randomly Suppose that PA)-0.6 and P(B)0.4 a student at a large y, and let A be the event that the selected student has a Visa card and B be the analogous event for MasterCard. (a) Could it be the case that P(A nB)-0.57 Why or why not? [Hint: For any two sets A and B if A is a subset of B then P(A) s P(8).] e No, this is not possible. Since A n B is contained in...
Consider randomly selecting a student at a certain university, and let A denote the event that the selected individual has a Visa credit card and B be the analogous event for a MasterCard. Suppose that P(A) = 0.3, P(B) = 0.4, and P(A ∩ B) = 0.05.(a) Compute the probability that the selected individual has at least one of the two types of cards (i.e., the probability of the event A ∪B).(b) What is the probability that the selected individual has neither type of card?(c) Describe, in terms of A and B, the event that the selected...
1 The Law of large numbers implies that the relative frequency of an event after many trials is increasingly predictable; this however cannot predict the outcome of any individual trial True False 2 In a batch of 25 products, there are 9 defective units. 6 of these have only minor defects while 3 have major defects. What is the probability that a randomly selected unit from the batch has major defects given that it is defective? 0.33 0.25 0.24 0.08...
MAT 150 Statistics Assignment #11 Binomial Probability Given the number of trials and the probability of success, determine the probability indicated: a. n-15, p. 0.4, find P(4 successes) b. n-12.p-0.2, find P(2 failures) c. n-20,p-0.05, find P(at least 3 successes) 1. An FBI survey shows that about 30% (i.e. 0.3) of all property crimes go solved. Suppose that in New York City 15 such crimes are committed and they are each deemed independent of each other 2. What is the...
Determine the probability P(3) for a binomial experiment with n - 12 trials and the success probability p=0.2. Then find the mean, variance, and standard deviation. Part 1 of 3 Determine the probability P(3). Round the answer to at least four decimal places. P(3)- Part 2 of 3 Find the mean. If necessary, round the answer to two decimal places. The mean is Part 3 of 3 Find the variance and standard deviation. If necessary, round the variance to two...
Probability, p. is a quantitative measure of how likely an event is to occur. Each of the subsequent questions details the likelihood of an event occurring. For each one, choose the value of p that best corresponds to that likelihood. The event is impossible and never occurs. Op=0.99 Op = 0 O p = 0.01 O p = 0.6 Op=1 Op= 0.3 The event is certain and always occurs. Op=0.01 Op=1 Op=0 Op = 0,3 Op=0,99 O p = 0.6...
Solve for c, d , e Problem2 Twenty people were asked were asked how many miles (to the nearest mile) they commute to work each day. Cumulative Relative Frequency Frequency Relative Frequency Miles 0.1 0.1 0.4 0.3 0.75 0.35 10 0.05 0.8 12 0.15 0.95 13 15 0.05 a. (396) Complete table (nn in relative frequency and cumulative relative frequency columns) b. (3%) Construct histogram E(396) Complete the box and whiskers plot B C D A-5 В 7 C= 10...
Here is a simple probability model for multiple-choice tests. Suppose that each student has probability p of correctly answering a question chosen at random from a universe of possible questions. (A strong student has a higher p than a weak student.) The correctness of answers to different questions are independent. Jodi is a good student for whom p = 0.78. (a) Use the Normal approximation to find the probability that Jodi scores 72% or lower on a 100-question test. (Round...
Suppose that each student has probability p of correctly answering a question chosen at random from a universe of possible questions. (A strong student has a higher p than a weak student.) The correctness of answers to different questions are independent. Jodi is a good student for whom p = 0.82. Use 4 decimal places. (a) Use the normal approximation to find the probability that Jodi scores 77% or lower on a 100-question test. (b) If the test contains 250...
In a survey of consumers aged 12 and older, respondents were asked how many cell phones were in use by the household. (No two respondents were from the same household.) Among the respondents, 205 answered "none," 289 said "one," 366 said "two," 134 said "three," and 45 responded with four or more. A survey respondent is selected at random. Find the probability that his/her household has four or more cell phones in use. Is it unlikely for a household to...