Questions on Algebra: Probability and statistics answered by real tutors!

Tutors Answer Your Questions about Probability-and-statistics (FREE)

Question 366924: IF YOU FLIP A COIN 7 TIMES WHAT IS THE PROBABILITY THAT IT WILL LAND ON HEADS 3 TIMES?
Click here to see answer by stanbon(57226)

Question 366922: IF WE ROLL A DICE 15 TIMES, WHAT IS THE PROBABILITY THAT WE WILL ROLL A 6 AT LEAST 13 TIMES?
Click here to see answer by stanbon(57226)

Question 366927: when a weighted coin is tossed 10 times and the probability of getting a head on one toss is .30 what is the probability of getting more than 5 heads?
Click here to see answer by stanbon(57226)

Question 366950: by measuring the amount of time it takes a component of a product to move from one workstation to the next, an engineer has estimated that the standard deviation is 3.92 seconds. Answer each of the following and (show all work).
(A). How many measurements should be made in order to be 90% certain that the maximum error of estimation will not exceed 2.0 sceonds?
(B). What sample is required for a maximum error of 1.5 seconds?11.37 and the sample size is 35, answer each of the following (show all work):
(A). Determine the maximum error of the estimate, E.
(B). Determine the confidence level used for the given confidence interval.

A confidence interval estimate for the population mean is given to be (37.46, 46.39). If the standard deviation is

Click here to see answer by stanbon(57226)

Question 366957: Acrylic bone cement is sometimes used in hip and knee replacements to fix an artificial joint in place. The force required to break an acrylic bone cement bond was measured for six specimens under specified conditions, and the resulting mean and standard deviation were 307.89 Newtons and 40.77 Newtons, respectively. Assuming that it is reasonable to assume that breaking force under these conditions has a distribution that is approximately normal and using 95% confidence level, estimate the true average breaking force f for acrylic bone cement under the specified conditions. (Use Table 3 in Appendix A. Round your answer to the nearest whole number.)
Click here to see answer by stanbon(57226)

Question 366964: A card is selected from a standard deck of 52 playing cards. A standard deck of cards has 12 face cards and four Aces (Aces are not face cards). Find the probability of selecting

· a five given the card is a not a club.
· a heart given the card is red.
· a face card, given that the card is black.
Click here to see answer by stanbon(57226)

Question 366962: A parent can choose from 5 types of protein, 6 vegetables and 4 desserts. If the parent serves a meal of 1 protein, 1 vegetable and 1 dessert to the family, how many different meals can be served
Click here to see answer by stanbon(57226)

Question 366980: Hello Tutors,
Glad you are here to help.
a sample of 4 different calculators is randomly selected from a group containging 18 that are defective. and 35 with no defects. What is the probability that at least 1 calculator is defective.
I started with adding all calculators together to get a total of 53. Then I divided 1/52 since we are looking for at least 1 defect out of 4. the answer I got was .0189. Is this correct?
If not, please solve and show your work.
Thank you kindly
Click here to see answer by stanbon(57226)

Question 366972: In San Francisco, 30% of workers take public transportation daily (USA Today, December 21,2005).

a.In a sample of 8 workers, what is the probability that exactly three workers take public transportation daily (to 4 decimals)?

b.In a sample of 8 workers, what is the probability that at least three workers take public transportation daily (to 4 decimals)?

Click here to see answer by robertb(4012)

Question 366909: Assume that the mean score on a certain aptitude test across the nation is 100, and that the standard deviation is 20 points. Find the probability that the mean aptitude test score for a randomly selected group of 150 8th graders is 100
Click here to see answer by robertb(4012)

Question 367005: a letter is known to have come either from LONDON or CLIFTON on the post mark only two consecutive letters ON are readable what is chance that the letter came from LONDON ?
Click here to see answer by Fombitz(13828)

Question 367001: 1. A 99% confidence interval estimate for a population mean was computed to be (29.2, 46.6). Determine the mean of the sample, which was used to determine the interval estimate (show all work).
2. A study was conducted to estimate the mean amount spent on birthday gifts for a typical family having two children. A sample of 170 was taken, and the mean amount spent was $248.72. Assuming a standard deviation equal to $48.31, find the 90% confidence interval for m, the mean for all such families (show all work).
Click here to see answer by robertb(4012)

Question 367004: I am using the TI 83Plus calculator, I am not sure of what tables I should use to solve this problem. Your help is appreciated.
The daily sales at a convience store produce a normal distribution with a mean of $1,250 and a standard deviation of $125.
What is the probability that the sales at this store on any given day are less than $1,310?our instructor insist we use a calculator to solve.
Click here to see answer by jim_thompson5910(28476)

Question 366842: A card is selected from a standard deck of 52 playing cards. A standard deck of cards has 12 face cards and four Aces (Aces are not face cards).
Find the probability of selecting

· a face card given the card is a not a club.
· a heart given the card is black.
· a Jack, given that the card is red.

Click here to see answer by Fombitz(13828)

Question 367007: a husband is left handed and his wife is right handed two children are born to the couple each child is just as likely to be the left handed as right handed what is the probability that both children are left handed also write which definition of probability will be applied here and why ?
2- a letter is taken out of ULTIMATE randomly and a letter is taken out of MULTIPLE what are chance that they are the same letters ?
Click here to see answer by robertb(4012)

Question 367043: What is the mean of the integers -49,000 to 50,000 inclusive?
Click here to see answer by robertb(4012)

Question 367065: Given that P(A) = 0.5, P(B) = 0.6, and P(A and B) = 0.30, determine P(A|B)
Click here to see answer by Jk22(389)

Question 367064: If P(A or B) = 0.7, P(A) = 0.3 and P(B) = 0.8, determine
P(A and B).
Click here to see answer by Jk22(389)

Question 367069: Hi tutors,
my instructor insists we use calculator to solve all problems. could you please solve this problem and show steps? I am using TI-83 plus. Thank you.
find the mean for the binomial distribution where n= 32 and p=.4
Click here to see answer by Fombitz(13828)

Question 367089: a company finds that 20% of thier employees resign within one year.
find the probability that among 30 employees, exactly 5 will resign
I got the answer of .421 but not sure, how to check it
thank you
Click here to see answer by stanbon(57226)

Question 366805: In a chemical plant, 24 holding tanks are used for final product storage. Four tanks are selected at random and without replacement. Suppose that six of the tanks contain material in which the viscosity exceeds the customer requirements.
a) Define events
b) Write Givens
c) What is the probability that exactly one tank in the sample contains high viscosity material ?
d) What is the probability that at least one tank in the sample contains high viscosity material?
e) In addition to the six tanks with high viscosity levels, four different tanks contain material with high impurities. What is the probability that exactly one tank in the sample contains high viscosity material and exactly one tank in the sample contains material with high impurities?

Click here to see answer by edjones(7569)

Question 366890: An instructor gives his class a set of 20 problems with the information that the next quiz will consist of a random selection of 10 of them. If a student has figured out how to do 17 of the problems, what is the probability the he or she will answer correctly at least 9 problems?
Click here to see answer by edjones(7569)

Question 367165: two teams, And B,play a series of games of team A has probability .4 of winning each game,is it to its advantage to play the best of three out of five games or the best four out of seven? Assume the outcomes of successive games are independent.
Click here to see answer by edjones(7569)

Question 367178: Two marbles are drawn without replacement from a box with 3 white, 2 green, 2 red, and 1 blue marble. Which is the probability if the first marble is blue and the second marble is white.
A) 3/7
B) 3/56
C) 2/7
D) 3/64
Click here to see answer by edjones(7569)

Question 367176: Two dice are rolled. Which is the probability that the score on the dice is either 12 or at most 4.
A) 2/9
B) 5/36
C) 7/36
D) 4/9
Click here to see answer by edjones(7569)

Question 367174: what is the probability of (AnB) if P(A) =.50; P(B) =.20; P(A/B) =.75 P(B/A) =.30 P(AuB) =.55
Click here to see answer by Edwin McCravy(8880)

Question 367183: Please help me with this homework question:
There are 9 students. 4 are going on a trip.
select a random sample from the students:
1. Kris
2. Tom
3. Joe
4. John
5. Jill
6. Bob
7. Dan
8. Kate
9. Matt
Read the list from left to right...
27798 12209 45287 71735
The simple random sample is?
I came up with Tom, Dan twice, and Matt.
Is this correct?
Click here to see answer by edjones(7569)

Question 367187: I keep getting told my answer is incorrect for this problem, please help!
20% of people own 3 or more cars. 100 households are selected. X= the number of households with 3 or more cars. The variance of X is?
I submitted 20 and then re-did the problem and came up with 4.
Now I am told that 4 is also incorrect.
Please help!
Click here to see answer by stanbon(57226)

Question 367170: A box contains 13 white cards numbered 1 through 13. List the sample space of the event choosing
one card with a number greater than 6.
1)
A) {1, 2, 3, ..., 13}
B) {7, 8, 9, 10, 11, 12, 13}
C) {6, 7, 8, 9, 10, 11, 12, 13}
D) {11}
Click here to see answer by edjones(7569)

Question 367172: 2) If a single card is drawn from a standard 52-card deck, in how many ways could it be a diamond or a face card?
A) 25
B) 13
C) 21
D) 22

Click here to see answer by edjones(7569)

Question 367154: Please help with this homework problem ASAP!!!
16% of Americans never have time to relax. You random sample 400 and count the number X that never have enough time to relax.
1) The mean of X is?
2)The Standard deviation of X is?
3) The probability that X is at least 80?
I answered:
1) 64
2) 3.46
3) about 0.0078
Is this correct?
Click here to see answer by edjones(7569)

Question 367350: You wish to learn the average age of an MBA student within 2 years and with 99% confidence. How large of a sample should you get?
Click here to see answer by stanbon(57226)

Question 367316: Mr. Butts smoked 15 cigarettes per day. Whats the probability a smoker will smoke less than Mr. Butts. mean = 11. standard deviation = 5
Click here to see answer by stanbon(57226)

Question 367344: IF A 6 FOOT ROPE IS CUT INTO TWO PIECES WHAT IS THE POSSIBILITIES OF ONE SIDE BEING GREATER THAN THREE
Click here to see answer by robertb(4012)

Question 367405: 9)

Tom sleeps an average of 7.55 hours a day. In one non-leap year, how many hours does Tom sleep?

9)

_______
A)

392.6 hours

B)

2793.5 hours

C)

2755.75 hours

D)

2719.25 hours

Click here to see answer by rfer(12646)

Question 367420: show me how to found the mean and standard deviation of four-digit uniformly distributed lottery numbers (0000 - 9999)
Click here to see answer by robertb(4012)

Question 367477: What critical region(s) for z would be used to test the hypotheses: H0:µ and Ha:µ≠10,for α = 0.025 ?

State the null hypothesis Ho and the alternative hypothesis Ha that would be used for a hypothesis test related to each of the following statements:
The mean weight of packages shipped on Air Express during the past month was less than 36.7 lb.

Click here to see answer by stanbon(57226)

Question 367510: An instructor gives his class a set of 15 problems with the information that the next quiz will consist of a random selection of 4 of them. If a student has figured out how to do 7 of the problems, what is the probability the he or she will answer correctly at least 3 questions?
Click here to see answer by robertb(4012)

Question 367574: A bag contains 4 red and 3 blue balls. John and Paul selects a ball at random and replaces it. The experiment is repeated 7 times. Find the probability that:
a) all 7 selections are red
b) at least 5 are red
c) no more than 2 are red
Click here to see answer by edjones(7569)

Question 367572: Mary selects three marbles from a jar containing 8 blue marbles and 2 yellow marbles. If the marble chosen after each selection is replaced before the next selection, find the probability distribution for the number of blue marbles drawn.
Click here to see answer by edjones(7569)

Older solutions: 1..45, 46..90, 91..135, 136..180, 181..225, 226..270, 271..315, 316..360, 361..405, 406..450, 451..495, 496..540, 541..585, 586..630, 631..675, 676..720, 721..765, 766..810, 811..855, 856..900, 901..945, 946..990, 991..1035, 1036..1080, 1081..1125, 1126..1170, 1171..1215, 1216..1260, 1261..1305, 1306..1350, 1351..1395, 1396..1440, 1441..1485, 1486..1530, 1531..1575, 1576..1620, 1621..1665, 1666..1710, 1711..1755, 1756..1800, 1801..1845, 1846..1890, 1891..1935, 1936..1980, 1981..2025, 2026..2070, 2071..2115, 2116..2160, 2161..2205, 2206..2250, 2251..2295, 2296..2340, 2341..2385, 2386..2430, 2431..2475, 2476..2520, 2521..2565, 2566..2610, 2611..2655, 2656..2700, 2701..2745, 2746..2790, 2791..2835, 2836..2880, 2881..2925, 2926..2970, 2971..3015, 3016..3060, 3061..3105, 3106..3150, 3151..3195, 3196..3240, 3241..3285, 3286..3330, 3331..3375, 3376..3420, 3421..3465, 3466..3510, 3511..3555, 3556..3600, 3601..3645, 3646..3690, 3691..3735, 3736..3780, 3781..3825, 3826..3870, 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