Questions on Normal Probability Models. Probability and area under the curve answered by real tutors!

Tutors Answer Your Questions about Normal-probability (FREE)

Question 1137103: Seven boys and five girls are going to a county fair to ride the teacup ride. Each teacup seats four persons. Tickets are assigned to specific teacups on the ride. If 12 tickets for the numbered seats are given out at random, determine the probability that four boys are given the first four seats on the first teacup.
Click here to see answer by VFBundy(438)

Question 1138258: a pollster plans to call adults. She has a list of names and numbers of 100 adults, consisting of 60 males and 40 females. she will make random selections and will not call the same person more than once.
a. consider the event of getting a male on first selection and getting a female on the second selection. are these independent or dependent events?
b. what is the probability of getting a male on the first selection and getting a female on the second selection?
Click here to see answer by Boreal(15235)

Question 1141240: A probability experiment consists of rolling a 6-sided die. Find the probability of the event below.
rolling a number less than 3
Click here to see answer by Boreal(15235)

Question 1141560: An office worker is allowed to take three 10-minute coffee breaks over the course a normal work day, which last from 9.am to 5p.m at randomly chosen times. If someone tried to ask the office worker at a random time during the work day, what is the probability that the worker will be on a coffee break?
A)1/6
B) 1/8
C)1/4
D)3/4
Click here to see answer by ikleyn(52786)

Question 1141563: A lollipop is chosen at random from a bucket of lollipops. The probability that the lollipop chosen will be grape flavored is 3/4, which of the following could not be the number of lollipops in the bucket.
A)16
B)28
C)49
D)144
Click here to see answer by Edwin McCravy(20056)

Question 1141562: A car company created a 90-second commercial and purchased enough air time for it to be played at 4 random times during prime time hours of 8p.m to 11 pm. If a viewer turns their television on at a random time during prime-time hours, what is the probability that the car commercial will be playing at the time?
A)1/120
B) 1/30
C) 1/45
D) 1/2
Click here to see answer by ikleyn(52786)

Question 1141567: A bowl contains a apples and b bananas and no other fruit, if a piece of fruit is picked at random from this bowl, the probability that an apple is picked is3/7 what is the value of a/b?
A) 3/10
B)3/7
C)4/3
D)3/4
Click here to see answer by ikleyn(52786)

Question 1141566: A bowl contains orange and green candles. The probability of randomly selecting an orange can is 1/4 and the probability of randomly selecting a green candy is 1/6. Which of the following could be the total number of candles in the bowl.
A)10
B)12
C)18
D)30
Click here to see answer by Boreal(15235)

Question 1141571: At a state fair, a game involves throwing a ring onto one of 60 bottles. If it’s is equally likely that the bottle will land on any of the bottles and 36 of these bottles are green. What is the probability that a ring will not land in a green bottle?
A) 1/36
B)2/5
C)3/5
D)5/6
Click here to see answer by ikleyn(52786)

Question 1141569: When an animated film is shown on network television, it requires a 90 minute block of time. Of that block of time, the movie itself if 63 minutes, credits take an addition 7 minutes and commercials take 20 minutes. At randomly chosen time, whatcis the probability that a commercial will not be airing?
A)5/7
B)2/9
C)2/7
D)7/9
Click here to see answer by ikleyn(52786)

Question 1141573: Leo’s pencil case contains 8 black pens, 6 blue pens and 2 red pens. He loses 4 pens, 2 of which are blue. If he then picks one pen out of the pencil case at random, what is the probability that it will be blue?
A) 1/3
B)1/4
C)1/6
D)1/8
Click here to see answer by jim_thompson5910(35256)

Question 1141619: In a bucket of 20 apples, 12 were green and the rest were red. 2 green apples are removed from the bucket. If one more apple is removed from the bucket, what is the probability that it is a red apple?
A) 2/5
B) 4/9
C) 5/9
D) 3/5
Click here to see answer by Boreal(15235)

Question 1141620: From a bookshelf containing 12 fiction and 15 non fiction books, 5 books are removed, 1 of which is non-fiction. If one more book is removed, what is the probability that it will be fiction?
A) 1/22
B) 1/11
C)4/11
D)1/2
Click here to see answer by Boreal(15235)

Question 1141621: A box initially contained 30 chess pawns, all either black or white. The probability of drawing a white pawn was 2/5. Some more white pawns we’re added to the box so that the probability of picking out a white pawn was raised to 1/2. How many white pawns were added to the box ?
A)2
B)3
C)6
D)18
Click here to see answer by Boreal(15235)

Question 1141627: Shonda is picking a movie to watch from her streaming queue of 18 dramas and 10 comedies. She decides she’s not interested in some of the movies anymore so she removes 8 of them, 2 of which are dramas. If she picks a movie at random from the remaining list, what is the probability that she will pick a comedy?
Click here to see answer by Edwin McCravy(20056)

Question 1141624: A bowl contains a total of 60 Bartlett, Bose and Anjou pears. The probability of randomly picking out a Barrtlett pear is 2/5 and the probability of picking out a Bose pear is 7/12. If all the Bose pears are removed, what is the probability of randomly picking An Anjou pear?
Click here to see answer by VFBundy(438)

Question 1141626: A box of chocolates contains only milk, dark and white chocolates. The probability of picking out a milk chocolate if 3/8. If there are 24 dark chocolates and 6 white chocolate , how many milk chocolate are there?
Click here to see answer by greenestamps(13200)

Question 1141630: Harold phone 36 apps, 4/9 of which are games. He downloads more games( and no other apps) so that 2/3 of the apps on his phone are now now games. How many games did he download?
Click here to see answer by ikleyn(52786)

Question 1141622: In a crate of 20 orange and yellow peppers, the probability of picking out a yellow pepper is 3/4. If 2 peppers are picked from this bucket, without replacement, what is the probability that they are both orange?
A)1/19
B)1/16
C)3/16
D)9/16
Click here to see answer by ikleyn(52786)

Question 1141625: A store sells only apple, orange and grape juice in its refrigerated case. The case contains 48 bottles of juice, 1/3 of which are apple. If there are 3 times as many bottles of orange juice as grape juice, what is the probability of reaching into the case and randomly picking out a bottle or orange juice??
Click here to see answer by VFBundy(438)

Question 1141623: A box contains 24 pieces of fruit: 7 cherry, 8 orange and 9 lemon. If no cherries are sold, what is the minimum number of lemons that can be sold in order to increase the probability of picking out a cherry to 50%?
A)0
B)1
C)2
D)3
Click here to see answer by jim_thompson5910(35256)

Question 1141637: A box contains 25 pieces of fruit: 7 cherry, 8 orange and 9lemon. If no cherries are sold, what is the minimum number of lemons that can be sold in order to increase the probability of picking out a cherry to 50%
A)0
B)1
C)2
D)3
Click here to see answer by ikleyn(52786)

Question 1141641: A container holds several different types of equally-sized cookies. The probability of picking an oatmeal cookie out of the container is 1/5. The probability of picking an oatmeal cookie out of a container, putting it back into the container and then picking up a chocolate chip cookie out of a container is 3/20. What is the probability of picking a chocolate chip cookie out of the container?
Click here to see answer by ikleyn(52786)

Question 1142617: A plane has three engines—a central engine and an engine on each wing. The plane will crash only if
the central engine fails and at least one of the two wing engines fails. The probability of failure
during any given flight is 0.005 for the central engine and 0.008 for each of the wing engines.
Assuming that the three engines operate independently, what is the probability that the plane will
crash during a flight?
Click here to see answer by ikleyn(52786)

Question 1142618: A company that makes corn flex is putting prize coupons in some of the boxes to as a promotional
strategy. On a certain day, a Supermarket has nine boxes of this product on its shelves and two of
these nine boxes contain prize coupons. Suppose that the customer who buys a box picks it from the
shelf at random. The store sells six of these nine boxes on that day. Find out the following
probabilities,
a. None of the six boxes sold contains a prize coupon.
b. At least one of the six boxes sold contains a prize coupon.
c. Both of the boxes with prizes are sold on that day.
Click here to see answer by greenestamps(13200)

Question 1143173: Which term of the AP: 21, 42, 63, 84,... is 210?
(A) 9th (B) 10th (C) 11th (D) 12th
Click here to see answer by math_helper(2461)

Question 1143757: Suppose a normal distribution has mean x¯ and standard deviation σ. If you happen to know x is 2σ LESS than x¯, then the z-score for x is what?
(The x¯ is the mean)
Click here to see answer by Shin123(626)

Question 1146680: An ordinary (fair) die is a cube with the numbers 1 through 6 on the sides (represented by painted spots). Imagine that such a die is rolled twice in succession and that the face values of the two rolls are added together. This sum is recorded as the outcome of a single trial of a random experiment.
Compute the probability of each of the following events.
Event : The sum is greater than 8
Event : The sum is divisible by 5 or 6 (or both).
Click here to see answer by ikleyn(52786)

Question 1147509: use the standard normal table to find the z-score that corresponds to the given percentile. If the area is not on the table, use the entry closest to the area. If the area is halfway between two entries, use the z-score halfway between the corresponding z-scores. P 72
Click here to see answer by Edwin McCravy(20056)

Question 1148853: Assume that the readings at freezing on a bundle of thermometers are normally distributed with a mean of 0°C and a standard deviation of 1.00°C. A single thermometer is randomly selected and tested. Find P61, the 61-percentile. This is the temperature reading separating the bottom 61% from the top 39%.
Click here to see answer by Boreal(15235)

Question 1150789: A store receives 5 red shirts and 10 green shirts. A random sample of 5 shirts selected. Determine the probability that
1. It contains 3 red shirts
2. It contain 1 red shirt.
3. It contain 3 green shirts
Click here to see answer by ikleyn(52786)

Question 1150897: What is the probability of choosing a multiple of 4 from the numbers 1 to 40 inclusive ?
Click here to see answer by MathLover1(20850)

Question 1150897: What is the probability of choosing a multiple of 4 from the numbers 1 to 40 inclusive ?
Click here to see answer by ikleyn(52786)

Question 1152655: The electric vehicle manufacturing company Tesla estimates that a driver who commutes 50 miles per day in a Model S will require a nightly charge time of around 1 hour and 45 minutes (105 minutes) to recharge the vehicle’s battery (Tesla company website). Assume that the actual recharging time required is uniformly distributed between 90 and 120 minutes.
a. Give a mathematical expression for the probability density function of battery recharging time for this scenario.
b. What is the probability that the recharge time will be less than 110 minutes?
c. What is the probability that the recharge time required is at least 100 minutes?
d. What is the probability that the recharge time required is between 95 and 110 minutes?
Click here to see answer by Boreal(15235)

Question 1152653: The electric vehicle manufacturing company Tesla estimates that a driver who commutes 50 miles per day in a Model S will require a nightly charge time of around 1 hour and 45 minutes (105 minutes) to recharge the vehicle’s battery (Tesla company website). Assume that the actual recharging time required is uniformly distributed between 90 and 120 minutes.
a. Give a mathematical expression for the probability density function of battery recharging time for this scenario.
b. What is the probability that the recharge time will be less than 110 minutes?
c. What is the probability that the recharge time required is at least 100 minutes?
d. What is the probability that the recharge time required is between 95 and 110 minutes?
Click here to see answer by Boreal(15235)

Question 1155261: The probability that a car will not require service for a fixed length of time is 0.95. An insurance company will sell a $3000 comprehensive coverage policy for this length of time for a premium of $300. Estimate the loss or profit for the insurance company ?
Click here to see answer by Boreal(15235)

Question 1156083: What is the probability as a percent of rolling a one on a decahedral number die?
Click here to see answer by ikleyn(52786)

Question 1156561: In how many ways can first, second, and third prizes be awarded in a contest with 405 contestants? Assume there are no ties.
Click here to see answer by ikleyn(52786)

Question 1156562: You pick 5 digits (0-9) at random without replacement, and write them in the order picked.
What is the probability that you have written the first 5 digits of your phone number? Assume there are no repeats of digits in your phone number.
Give answer as a fraction.
Click here to see answer by greenestamps(13200)

Question 1156564: A company estimates that 0.8% of their products will fail after the original warranty period but within 2 years of the purchase, with a replacement cost of $50.
If they offer a 2 year extended warranty for $5, what is the company's expected value of each warranty sold?
Click here to see answer by Boreal(15235)

Question 1157032: A single 6-sided die is rolled 8 times. What is the probability that either 4 or 5 was rolled exactly twice.
Click here to see answer by ikleyn(52786)

Older solutions: 1..45, 46..90, 91..135, 136..180, 181..225, 226..270