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

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

Question 395188: How many 4-digit numbers can be formed using the digits 1, 2, 3, 4, 5, 6, 7 if repetition of digits is
not allowed
Click here to see answer by robertb(4012)

Question 395179: Determine whether each sitution would producce a random sample.Write yes or no and explain your answer.
Pointing with a pencel at a class liat with your eyes close as away to find a sample of students in your class
Asking every twenties person on a list of registered voters to determine which political candicateis favored

Click here to see answer by robertb(4012)

Question 395266: A retailer believes that the proportion of items returned after purchase is less at location A than all other locations. The other locations have a 14% return rate. Write the null and alternative hypothesis for this problem. Would you use a z test or a t-test)?
Click here to see answer by stanbon(57984)

Question 395265: Choose the correct decision rule for a “right-tailed” t-test where the critical value is 2.05.
a. Reject H0 if t < 2.05
b. Reject H0 if z >2.05
c. Reject H0 if t > 2.05
d. Reject H0 if t < .05

Click here to see answer by jrfrunner(365)

Question 395264: If you are performing a one sample hypothesis test of the mean and the standard deviation of the population is unknown, do you use a t-test or a z-test?
Click here to see answer by jrfrunner(365)

Question 395263: Looking for help with the following:
Using the p-value from Question #1, would you accept or reject the null hypothesis at the 95% confidence level? Why or why not?
Note: Question #1 is:
Provide the p-value for a left-tailed one sample hypothesis test (z test) where the test statistic is -2.6. You must show your work or provide the Excel formula that you used.

Thanks!
Click here to see answer by jrfrunner(365)

Question 395262: Looking for help with the following:
Provide the p-value for a left-tailed one sample hypothesis test (z test) where the test statistic is -2.6. You must show your work or provide the Excel formula that you used.
Thanks!
Click here to see answer by jrfrunner(365)

Question 395259: A chemical company produces a substance composed of 98% cracked corn particles and 2% zinc phosphide for use in controlling rat population in sugarcane field. Production must be carefully controlled to maintain the 2% zinc phosphide because too much zinc phosphide will cause damage to the sugarcane and too little will be ineffective in controlling the rate population. Records from past production indicate that the distribution of the actual percentage of zinc phosphide present in the substance is approximately mound-shaped with a mean of 2.0% and standard deviation o 0.08%.
a) If the production line is operating correctly, approximately what proportion of batches from a days' production will contain less than 1.84% of zinc phosphid?
b) Suppose one batch chosen randomly actually contains 1.80% zinc phosphide. Does this indicate that there is too little zinc phosphide in today's production? Explain your reasoning.
Click here to see answer by jrfrunner(365)

Question 395358: Which of the following is equivalen to sin(data)+cot(data)cos(data)
F)2sin(data)
G1/sin(data)
H)cos^2(data)
J)sin(data)+cos(data)/sin^2(data)
The key is G

Click here to see answer by jim_thompson5910(28717)

Question 395418: If 2 cards are selected from a standard deck of 52 cards without replacement, find these probabilities.
a. Both are spades.
b. Both are the same suit.

c. Both are kings.

Click here to see answer by jim_thompson5910(28717)

Question 395522: a 3digit area code is required. 1 digit must be an odd number 2nd digit must be an zero or one and the 3rd digit can be anything. how many area codes are possible
Click here to see answer by stanbon(57984)

Question 395578: Provide the p-value for a left-tailed one sample hypothesis test (z test) where the test statistic is -2.6. You must show your work or provide the Excel formula that you used.

Click here to see answer by stanbon(57984)

Question 395638: What is the sample mean of 19,11,1,7,12
Click here to see answer by ewatrrr(10682)

Question 395663: P(X < n) is always equal to 1 – P(X > n), regardless of the type of probability distribution.
True
False

Click here to see answer by richard1234(5390)

Question 395670: In normal distributions, if P(X < k) = 0.50, then k is the median of the distribution.
True
False

Click here to see answer by jrfrunner(365)

Question 395677: what's the probability of pulling a heart or a queen from a standard deck of a cards?
Click here to see answer by solver91311(17077)

Question 395679: Two girls, Anna and Cathy, attempt independently to solve a problem. The probability of Anna solving it is 0.60 and the probability of Cathy solving it is 0.30. Find the probability that only one of them will be able to solve it.
Click here to see answer by jrfrunner(365)

Question 395671: The pH of a chemical process is normally distributed with mean of 6.00 and standard deviation of 0.90. What is the probability of a pH between 5.85 and 7.40?
Click here to see answer by ewatrrr(10682)

Question 395683: In a certain group of students, the probability that a student have experienced chickenpox is 0.7 and the probability of haven’t experienced it yet is 0.30. If 5 students are randomly selected with replacement, what is the probability that exactly one of them have experienced chickenpox?
Click here to see answer by ewatrrr(10682)

Question 395666: A biologist studying the germination rate of a seed finds that 90% of the seeds of a given type germinate. If she has a box of 10 seeds, what is the probability that exactly 6 of the seeds germinate?

Click here to see answer by ewatrrr(10682)

Question 395695: A matching type of test is given. There are 10 statements in the left and 12 choices to choose from in the right column. If an answer can be used only once, what is the probability that a student can guess all the answers correctly?

a. 12P10

b. 12C10

c. 1/12P10

d. 1/12C10

Click here to see answer by stanbon(57984)

Question 395744: what is the probability of 4 calculator batteries with a 90% chance of lasting one year?
Click here to see answer by ewatrrr(10682)

Question 395711: If P(A) = .20, P(B) = .30, and P(A and B) = .15,
what is P(A|B)??
Click here to see answer by Edwin McCravy(8999)

Question 395934: I am looking to solve this problem.
I do not know what the difference between these are:
Is this the right answer to this (2.326*500/10)² = 13,525.69
or would this be the way to do this ((2.326*500)/10)² =
Looking to find the number to survey, using 98% confidence level and a deviation of 500 and be wtihin 10 plus or minus.
Thanks
Click here to see answer by stanbon(57984)

Question 395491: 5) A 3 member arts council is to be chosen from 9 students, 6 of whom are female. the positions are president secretary and tresurer. what is the probability that
A) that committee is all female?
B) the committee is comprised of the three youngest females
C) the younest girl is president, second younger is secretary and third youngest is tresurer
Click here to see answer by sudhanshu_kmr(1152)

Question 396067: 397 C 3 =10,349,790
How do you get this answer?

Click here to see answer by sudhanshu_kmr(1152)

Question 396240: In a company, 85% of the employees are females. If 765 males work for the company, what is the total number of employees?
Click here to see answer by ewatrrr(10682)

Question 396240: In a company, 85% of the employees are females. If 765 males work for the company, what is the total number of employees?
Click here to see answer by rfer(12731)

Question 396262: what is the answer to these problems? round each number to the nearest thousand
1. 12,345 2. 38,234 3. 79,124
can u plzzz solve the problems???????
Click here to see answer by ewatrrr(10682)

Question 396321: How do I find the sample size of a sample when I am given the Margin of Error? An example is I need to find the sample size when my margin of error is +- 4%.I know the formula for finding the margin of error for a sample size, which would be where (N) is the sample size. To get a sample size from the margin of error, which in this case is 4% I tried and I get 4 *10^4. (I put that in scientific notation the best I knew how.) I also tried
I don't know how to get the Sample Size when given the margin of error.
Click here to see answer by stanbon(57984)

Question 396656: A six sided number cube is rolled 30 times. The number cube showed a number greater than four 8 times. What is the difference between the experimental probability and the theoretical probability of rolling a number greater than four?
Click here to see answer by ewatrrr(10682)

Question 397043: If posts are spaced 9 feet apart, how many posts are needed for 54 feet of straight-line fence?
Click here to see answer by jim_thompson5910(28717)

Question 397035: Find the z-score for the given raw score, mean, and standard deviation. Assume a normal probability distribution.
Raw score = 66, μ = 60, and σ = 6.
Click here to see answer by jim_thompson5910(28717)

Question 397044: what are the odds that the card is not the ace of spades?
Click here to see answer by stanbon(57984)

Question 397044: what are the odds that the card is not the ace of spades?
Click here to see answer by richard1234(5390)

Question 397022: Evaluate each expression 5! - 2!
Click here to see answer by jim_thompson5910(28717)

Question 397113: If the probability of rain is 5/9, what are the odds against rain?
The answer goes in the format " " to " "
Click here to see answer by robertb(4012)

Question 397124: Hello,
I have this math brain teaser that is killing me. Can you help please?
In a dark room, a boxed is filled with different colored balls there are 14 blue, 13 red, 22 black and 18 green. What is the smallest number of balls you need to select to get at least 4 of the same color.
Kindest regards,
Candy
Click here to see answer by solver91311(17077)

Question 397256: Consider the numbers between 100 and 400. How many of these numbers are even and have no repetition of digits?
Case 1: 2 or 3 in first position and 0 in last position: 2x8x1 = 16
Case 2: 1 or 3 in first position and 2 in last position: 2x8x1 = 16
Case 3: 1,2 or 3 in first position and 4,6,8 in last position: 3x8x3 = 72
Total:104....BUT the answer is 112. What am I missing?

Click here to see answer by sudhanshu_kmr(1152)

Question 397264: How do I find the domain of f(x)=ln(ln(x))without using my calculator?
Click here to see answer by josmiceli(9817)

Question 397289: Fry Brothers Heating and Air Conditioning, Inc. employees Larry Clark and George Murnen to make service calls to repair furnaces and air conditioning units in homes. Tom Fry, the owner, would like to know whether there is a difference in the mean number of service calls they make per day. A random sample of 40 days last year showed that Larry Clark made an average of 4.77 calls per day, with a standard deviation of 1.05 calls per day. For a sample of 50 days George Murnen made an average of 5.02 calls per day, with a standard deviation of 1.23 calls per day. At the .05 significance level, is there a difference in the mean number of calls per day between the two employees? What is the p-value?
Click here to see answer by stanbon(57984)

Question 397287: The following data on annual rates of return were collected from five stocks listed on the New York Stock Exchange (“the big board”) and five stocks listed on NASDAQ. At the .10 significance level, can we conclude that the annual rates of return are higher on the big board?
NYSE Nasdaq
17.16 15.80
17.08 16.28
15.51 16.21
8.43 17.97
25.15 7.77

Click here to see answer by stanbon(57984)

Question 397320: In a high school year book, there is a picture of each pair of students in the graduating class, and a picture of each student in the graduating class. There are a total of 1275 pictures. What is the sum of the digits of the number of students in the graduating class?
Choose the answer and explain the reason to choose your response:
7
6
8
5
Click here to see answer by solver91311(17077)

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, 3871..3915, 3916..3960, 3961..4005, 4006..4050, 4051..4095, 4096..4140, 4141..4185, 4186..4230, 4231..4275, 4276..4320, 4321..4365, 4366..4410, 4411..4455, 4456..4500, 4501..4545, 4546..4590, 4591..4635, 4636..4680, 4681..4725, 4726..4770, 4771..4815, 4816..4860, 4861..4905, 4906..4950, 4951..4995, 4996..5040, 5041..5085, 5086..5130, 5131..5175, 5176..5220, 5221..5265, 5266..5310, 5311..5355, 5356..5400, 5401..5445, 5446..5490, 5491..5535, 5536..5580, 5581..5625, 5626..5670, 5671..5715, 5716..5760, 5761..5805, 5806..5850, 5851..5895, 5896..5940, 5941..5985, 5986..6030, 6031..6075, 6076..6120, 6121..6165, 6166..6210, 6211..6255, 6256..6300, 6301..6345, 6346..6390, 6391..6435, 6436..6480, 6481..6525, 6526..6570, 6571..6615, 6616..6660, 6661..6705, 6706..6750, 6751..6795, 6796..6840, 6841..6885, 6886..6930, 6931..6975, 6976..7020, 7021..7065, 7066..7110, 7111..7155, 7156..7200, 7201..7245, 7246..7290, 7291..7335, 7336..7380, 7381..7425, 7426..7470, 7471..7515, 7516..7560, 7561..7605, 7606..7650, 7651..7695, 7696..7740, 7741..7785, 7786..7830, 7831..7875, 7876..7920, 7921..7965, 7966..8010, 8011..8055, 8056..8100, 8101..8145, 8146..8190, 8191..8235, 8236..8280, 8281..8325, 8326..8370, 8371..8415, 8416..8460, 8461..8505, 8506..8550, 8551..8595, 8596..8640, 8641..8685, 8686..8730, 8731..8775, 8776..8820, 8821..8865, 8866..8910, 8911..8955, 8956..9000, 9001..9045, 9046..9090, 9091..9135, 9136..9180, 9181..9225, 9226..9270, 9271..9315, 9316..9360, 9361..9405, 9406..9450, 9451..9495, 9496..9540, 9541..9585, 9586..9630, 9631..9675, 9676..9720, 9721..9765, 9766..9810, 9811..9855, 9856..9900, 9901..9945, 9946..9990, 9991..10035, 10036..10080, 10081..10125, 10126..10170, 10171..10215, 10216..10260, 10261..10305, 10306..10350, 10351..10395, 10396..10440, 10441..10485, 10486..10530, 10531..10575, 10576..10620, 10621..10665, 10666..10710, 10711..10755, 10756..10800, 10801..10845, 10846..10890, 10891..10935, 10936..10980, 10981..11025, 11026..11070, 11071..11115, 11116..11160, 11161..11205, 11206..11250, 11251..11295, 11296..11340, 11341..11385, 11386..11430, 11431..11475, 11476..11520, 11521..11565, 11566..11610, 11611..11655, 11656..11700, 11701..11745, 11746..11790, 11791..11835, 11836..11880, 11881..11925, 11926..11970, 11971..12015, 12016..12060, 12061..12105, 12106..12150, 12151..12195, 12196..12240, 12241..12285, 12286..12330, 12331..12375, 12376..12420, 12421..12465, 12466..12510, 12511..12555, 12556..12600, 12601..12645, 12646..12690, 12691..12735, 12736..12780, 12781..12825, 12826..12870, 12871..12915, 12916..12960, 12961..13005, 13006..13050, 13051..13095, 13096..13140, 13141..13185, 13186..13230, 13231..13275, 13276..13320, 13321..13365, 13366..13410, 13411..13455, 13456..13500, 13501..13545, 13546..13590, 13591..13635, 13636..13680, 13681..13725, 13726..13770, 13771..13815, 13816..13860, 13861..13905, 13906..13950, 13951..13995, 13996..14040, 14041..14085, 14086..14130, 14131..14175, 14176..14220, 14221..14265, 14266..14310, 14311..14355, 14356..14400, 14401..14445, 14446..14490, 14491..14535, 14536..14580, 14581..14625, 14626..14670, 14671..14715, 14716..14760, 14761..14805, 14806..14850, 14851..14895, 14896..14940, 14941..14985, 14986..15030, 15031..15075, 15076..15120, 15121..15165, 15166..15210, 15211..15255, 15256..15300, 15301..15345, 15346..15390, 15391..15435, 15436..15480, 15481..15525, 15526..15570, 15571..15615, 15616..15660, 15661..15705, 15706..15750, 15751..15795, 15796..15840, 15841..15885, 15886..15930, 15931..15975, 15976..16020, 16021..16065, 16066..16110, 16111..16155, 16156..16200, 16201..16245, 16246..16290, 16291..16335, 16336..16380, 16381..16425, 16426..16470, 16471..16515, 16516..16560, 16561..16605, 16606..16650, 16651..16695, 16696..16740, 16741..16785, 16786..16830, 16831..16875, 16876..16920, 16921..16965, 16966..17010, 17011..17055, 17056..17100, 17101..17145, 17146..17190, 17191..17235, 17236..17280, 17281..17325, 17326..17370, 17371..17415, 17416..17460, 17461..17505, 17506..17550, 17551..17595, 17596..17640, 17641..17685, 17686..17730, 17731..17775, 17776..17820, 17821..17865, 17866..17910, 17911..17955, 17956..18000, 18001..18045, 18046..18090, 18091..18135, 18136..18180, 18181..18225, 18226..18270, 18271..18315, 18316..18360, 18361..18405, 18406..18450, 18451..18495, 18496..18540, 18541..18585, 18586..18630, 18631..18675, 18676..18720, 18721..18765, 18766..18810, 18811..18855, 18856..18900, 18901..18945, 18946..18990, 18991..19035, 19036..19080, 19081..19125, 19126..19170, 19171..19215, 19216..19260, 19261..19305, 19306..19350, 19351..19395, 19396..19440, 19441..19485, 19486..19530, 19531..19575, 19576..19620, 19621..19665, 19666..19710, 19711..19755, 19756..19800, 19801..19845, 19846..19890, 19891..19935, 19936..19980, 19981..20025, 20026..20070, 20071..20115, 20116..20160, 20161..20205, 20206..20250, 20251..20295, 20296..20340, 20341..20385, 20386..20430, 20431..20475, 20476..20520, 20521..20565, 20566..20610, 20611..20655, 20656..20700, 20701..20745, 20746..20790, 20791..20835, 20836..20880, 20881..20925, 20926..20970, 20971..21015, 21016..21060, 21061..21105, 21106..21150, 21151..21195, 21196..21240, 21241..21285, 21286..21330, 21331..21375, 21376..21420, 21421..21465, 21466..21510, 21511..21555