Chapter 4 basic concepts of probabilty
For a certain horse race, the odds in favor of a certain horse finishing in second place are given as 71 to 29. Express the indicated degree of likelihood as a probability value between 0 and 1 inclusive.
0.71
In a particular survey of internet users, 3782 respondents say that they use social networking sites and 1481 respondents say that they do not use social networking sites. What is the probability that a randomly selected person uses a social networking site? Does that result suggest that it is likely (with a probability of 0.5 or greater) for someone to use social networking sites?
0.719 Yes, because the probability of a respondent using social media is greater than 0.5
In a genetics experiment on peas, one sample of offspring contained 368 green peas and 127 yellow peas. Based on those results, estimate the probability of getting an offspring pea that is green. Is the result reasonably close to the value of 34 that was expected?
0.743 yes it is reasonably close
Among 350 randomly selected drivers in the 16−18 age bracket, 283 were in a car crash in the last year. If a driver in that age bracket is randomly selected, what is the approximate probability that he or she will be in a car crash during the next year? Is it unlikely for a driver in that age bracket to be involved in a car crash during a year? Is the resulting value high enough to be of concern to those in the 16−18 age bracket? Consider an event to be "unlikely" if its probability is less than or equal to 0.05.
0.809 Would it be unlikely for a driver in that age bracket to be involved in a car crash this year? No Part 3 Is the probability high enough to be of concern to those in the 16−18 age bracket? yes
Homework:17. Module 4: Basic Concepts of Probability Question 15, 4.1.21 Part 2 of 2 HW Score: 93.87%, 93.87 of 100 points Points: 3 of 3 Save Question content area top Part 1 In a test of a gender-selection technique, results consisted of 254 baby girls and 15 baby boys. Based on this result, what is the probability of a girl born to a couple using this technique? Does it appear that the technique is effective in increasing the likelihood that a baby will be a girl?
0.944 yes
Assume that boys and girls are equally likely. Find the probability that when a couple has three children, there are exactly 0 boys.
1/8
Which of the following values cannot be probabilities? 0.09, 2, 5/3, 0, 1, 3/5, 1.18, square root of two
5/3, -0.58, 1.18, square root of 2
On their first date, Kelly asks Mike to guess the date of her birth, not including the year. Complete parts a through c below.
. What is the probability that Mike will guess correctly? (Ignore leap years.) 1/365 (Type an integer or a simplified fraction.) Part 2 b. Would it be unlikely for him to guess correctly on his first try? D. Yes, it is unlikely for Mike to guess correctly on his first try, as the probability of a correct guess is very low. Your answer is correct. Part 3 c. If you were Kelly, and Mike did guess correctly on his first try, would you believe his claim that he made a lucky guess, or would you be convinced that he already knew when you were born? Mike already knew, as the probability of a correct guess is very low.
It is impossible to get 7 kings when selecting cards from a shuffled deck. Express the indicated degree of likelihood as a probability value between 0 and 1 inclusive
0
In a certain study, the chances of encountering a car crash on the road are stated as "1 in 20." Express the indicated degree of likelihood as a probability value between 0 and 1 inclusive.
0.05
Express the indicated degree of likelihood as a probability value between 0 and 1. When using a computer to randomly generate the last digit of a phone number to be called for a survey, there is 1 chance in 10 that the last digit is zero.
0.1
In a certain study, the chances of encountering a car crash on the road are stated as 30 out of 100. Express the indicated degree of likelihood as a probability value between 0 and 1 inclusive
0.3
Express the indicated degree of likelihood as a probability value between 0 and 1. Based on a survey of hiring managers who were asked to identify the biggest mistakes that job candidates make during an interview, there is a 50-50 chance that they will identify "inappropriate attire."
0.5
For a certain true or false test question, the odds of a random guess being correct are given as 50 to 50. Express the indicated degree of likelihood as a probability value between 0 and 1 inclusive.
0.5
In a test of a gender-selection technique, results consisted of 214 baby girls and 199 baby boys. Based on this result, what is the probability of a girl born to a couple using this technique? Does it appear that the technique is effective in increasing the likelihood that a baby will be a girl?
0.518 no
Assume that 1200 births are randomly selected and 591 of the births are girls. Use subjective judgment to describe the number of girls as significantly high, significantly low, or neither significantly low nor significantly high
The number of girls is neither significantly low nor significantly high.
Four of the 50 digital video recorders(DVRs) in an inventory are known to be defective. What is the probability that a randomly selected item isdefective?
The probability is 0.08. (Type an integer or a decimal. Do not round.)
Let A denote the event of placing a $1 straight bet on a certain lottery and winning. Suppose that, for this particular lottery, there are 8,000 different ways that you can select the four digits (with repetition allowed) in this lottery, and only one of those four-digit numbers will be the winner. What is the value of P(A)? What is the value of P(A)?
What is the value of P(A)? P(A)=.00013 (Round to five decimal places as needed.) Part 2 What is the value of P(A)? P(A)=0.99987 (Round to five decimal places as needed.)
Homework:17. Module 4: Basic Concepts of Probability Question 21, 4.1.27 Part 3 of 3 HW Score: 93.87%, 93.87 of 100 points Points: 4 of 4 Save Question content area top Part 1 Each of two parents has the genotype red/blond, which consists of the pair of alleles that determine hair color, and each parent contributes one of those alleles to a child. Assume that if the child has at least one red allele, that color will dominate and the child's hair color will be red. a. List the different possible outcomes. Assume that these outcomes are equally likely. b. What is the probability that a child of these parents will have the blond/blond genotype? c. What is the probability that the child will have red hair color?
a) Red/ red, red/ blond, blond/ red, and blond/ blond b/ the probability that the child of these parents will have the blond/ blond genotype is 0.25 c) the prob that the child will have red hair color is 0.75
Men have XY (or YX) chromosomes and women have XX chromosomes. X-linked recessive genetic diseases (such as juvenile retinoschisis) occur when there is a defective X chromosome that occurs without a paired X chromosome that is not defective. Represent a defective X chromosome with lowercase x, so a child with the xY or Yx pair of chromosomes will have the disease and a child with XX or XY or YX or xX or Xx will not have the disease. Each parent contributes one of the chromosomes to the child. Complete parts a through d below.
a. If a father has the defective x chromosome and the mother has good XX chromosomes, what is the probability that a son will inherit the disease? 0 (Type an integer or a decimal. Do not round.) Part 2 b. If a father has the defective x chromosome and the mother has good XX chromosomes, what is the probability that a daughter will inherit the disease? 0 (Type an integer or a decimal. Do not round.) Part 3 c. If a mother has one defective x chromosome and one good X chromosome and the father has good XY chromosomes, what is the probability that a son will inherit the disease? 0.5 (Type an integer or a decimal. Do not round.) Part 4 d. If a mother has one defective x chromosome and one good X chromosome and the father has good XY chromosomes, what is the probability that a daughter will inherit the disease? 0 (Type an integer or a decimal. Do not round.)
a. Find the probability that when a single six-sided die is rolled, the outcome is 1. b. Find the probability that when a coin is tossed, the result is tails. c. Find the probability that when a six-sided die is rolled, the outcome is 15.
a. The probability of rolling a 1 on a six-sided die is 0.167. (Round to three decimal places as needed.) Part 2 b. The probability of a result of tails when tossing a coin is 0.5. (Round to three decimal places as needed.) Part 3 c. The probability of rolling a 15 on a six-sided die is 0. (Round to three decimal places as needed.)
On their first date, Kelly asks Mike to guess the date of her birth, not including the year. Complete parts a through c below
a. What is the probability that Mike will guess correctly? (Ignore leap years.) 1/365 (Type an integer or a simplified fraction.) Part 2 b. Would it be unlikely for him to guess correctly on his first try? D. Yes, it is unlikely for Mike to guess correctly on his first try, as the probability of a correct guess is very low. Your answer is correct. Part 3 c. If you were Kelly, and Mike did guess correctly on his first try, would you believe his claim that he made a lucky guess, or would you be convinced that he already knew when you were born? Mike already knew, as the probability of a correct guess is very low.
