#### • Class 11 Physics Demo

Explore Related Concepts

#### • how to find the theoretical probability

Question:How to identified between conditional probability.addition rule, and multiplication..is confusing me especially i m not good in maths...thanks for those who briefly explain it to me..:D hermm..just briefly explain...a website...is too detail and i cant get it..thanks..

Answers:If you want the probability of A and B, P(A B) it may or may not equal P(A)*P(B) it will never be larger than the smaller of the two P(A) or P(B) and it might be as small as 0 if A and B are mutually exclusive. So how do you find the P(A B) if it is not given. If A and B are independent, which means if A happens it will neither help or hinder the chance that B will happen then P(A B) = P(A)*P(B) If they are not independent and you know the conditional probability of P(A|B) then P(A B) = P(A|B)*P(B). (With a little Algebra that formula can be used to find P(A|B).) If you need to find the probability of A or B you will need to add probabilities, but unless P(A B) is zero the P(A) + P(B) will not work since the P(A B) will be counted twice. (Make a Venn diagram to confirm this fact.) The Probability of A or B: P(A B) = P(A) + P(B) - P(A B)

Question:An airline claims that the no-show rate for passengers booked on its flights is less than 6%. Of 380 randomly selected reservations, 18 were no-shows. Find the P-value for a test of the airline's claim. I am not worried so much about the answer as to HOW to get the answer.

Answers:Let P be the proportion of no-show rate for passengers booked on its flights. Ho: P =0.06 Ha: P < 0.06 Estimated p = 18 / 380 = 0.0474 Variance of proportion = p*(1-p)/n = 0.06(0.94)/380 =0.0001484 S.D. of p is sqrt[0.000148] = 0.0122 Z = ( 0.0474 - 0.06 ) / 0.0122 = -1.0368 From Normal probability table , P( z < -1.0368) = 0.1492 p-value = 0.1492

Question:bromothymol blue changes color from yellow in acid to blue in base between pH 6.0 and pH 7.6. If you only had this indicator and a sample of 1 mol/L NaOH, explain how you could determine the strength of different acids

Answers:Dip the bromothymol blue indicator into the NaOH. Look at which color the bromothymol blue indicator changed to. If it's yellow, or nearest to yellow, the pH would be around 6.0, but if it's blue, or closest to blue, then the pH would be around 7.6. Then, look at the pH scale and find the number. You will see if it is an acid or base. Acid: -1.0 to 6.9 Base: 7.1 to 14

Question:Find the indicated binomial probabilities. Round to the nearest 3 decimal places. For part d and e: 4. In a local college, 20% of the math majors are women. Ten math majors are chosen at random. (1 points each) a.What is the probability that exactly 2 are women? b. What is the probability that 2 or less women are selected? c. What is the probability that no women are selected? d. Find the mean e. Find the variance 2

Answers:This is a question best put before the answers under the Mathematics forum. That said, since this is homework, what are your solutions so we can assist in helping you learn the process of solving and whether or not you've computed the answers correctly?