Tutors Answer Your Questions about Normal-probability (FREE)
Question 1076709: Maggie pays $15 per month for her cell phone. She gets the first 200 minutes in the month free. After that it costs 8 cents per minute. Below is a table of the first 4 months of Maggies cell phone usage. What is the mean cost per month for Maggies cell phone?
Graph in the link: http://prntscr.com/ewxgza
Click here to see answer by josgarithmetic(39617)  |
Question 1078213: The monthly salary in a big organization is normally distributed with mean Rs. 3000, and standard deviation of Rs. 250. What should be the minimum salary of a worker in the organization so that the probability that he belongs to top 5% workers.
Click here to see answer by stanbon(75887) |
Question 1087209: Nielsen Rating: The television show nbc Sunday night football broadcast a game between the colts and patriots and received a share of 22, meaning that among the tv sets in use, 22% are turned to that game (based on data from Nielsen Media Research). An advertiser wants to obtain a second opinion by conducting its own surveys and a pilot survey begins with 20 households having tv sets in use at the time of that same nbc Sunday night football broadcast.
a. Find the probability that none of the households are turned to nbc Sunday night football (3 digits)
b. Find the probability that at least one of the households is turned to nbc Sunday night football.(3 digits)
c. Find the probability that at most one of the households is turned to nbc Sunday night football (3 digits)
d. If at most one household is turned to nbc Sunday night football, does it appear that the 22% share value is wrong? Why or why not?
Please show me how you got the answer. (I need help)
Click here to see answer by mathmate(429)  |
Question 1096633: It has been reported that the average credit card debt for college seniors at the college book
store for a specific college is $3262 and the standard deviation is $1100. The student senate at
a large university feels that their seniors have debt much less than this, so it conducts a study of
50 randomly selected seniors and finds that average debt is $2995. Is the student senate correct
with 0.05.
Click here to see answer by Boreal(15235)  |
Question 1099250: Can someone help me? Thank you.
A production line produces bags of sugar that follow a normal distribution with a mean weight of 1.01kg and a standard deviation of 0.02kg.
If P(X≥b)=0.9330, then what is the value of b?
Click here to see answer by Theo(13342)  |
Question 1103312: There is a probability of 0.04 that a lamp purchased at a given store doesnt work. A person purchases 3 lamps. a) Define a random variable as the number of non-working lamps. What is the sample space? b) Find the probability distribution.
Click here to see answer by stanbon(75887) |
Question 1105390: Last year income (in minimum wages) in city A was well represented by X ~ N (2,5; 4). An economist wants to test whether there was an increase in average income this year, and for that she took AAS of size n = 64.
a) construct a hypothesis test for this situation with α = 0.05 (define a decision rule)
b) Suppose that X (x-bar) = 2.8 was observed. What is the end of the test? Construct a confidence interval (μ, 0.95)
Click here to see answer by Boreal(15235) |
Question 1105395: The elevator installed in a building can carry up to 10 people or a maximum weight of 800 kg. It is known that the weight of the people in this building follows a normal distribution with mean μ = 70 and variance σ^2 = 90. Calculate the probability that the sum of the weights of 10 persons together in the elevator exceeds the maximum weight.
Click here to see answer by Boreal(15235) |
Question 1109746: To win the lottery in a certain state you must correctly select 6 distinct numbers from a collection of 60 numbers (1 through 60). You will win if your numbers match the winning numbers in any order. What is the probability of winning the lottery?
Click here to see answer by Alan3354(69443)  |
Question 1112389: Use the formula
C(n, x)pxqn − x
to determine the probability of the given event. (Round your answer to four decimal places.)
The probability of at least three successes in six trials of a binomial experiment in which
p = 1/2
Click here to see answer by Boreal(15235) |
Question 1114452: Women have head circumferences that are normally distributed with a mean given by mu equals 24.83 in., and a standard deviation given by sigma equals 0.8 in.
b. If the company wants to produce hats to fit all women except for those with the smallest 1.5% and the largest 1.5% head circumferences, what head circumferences should be accommodated?
Click here to see answer by stanbon(75887) |
Question 1113831: Jessica is studying combinatorics during a 7-week period. She will study a positive integer number of hours every day during the 7 weeks (so, for example, she won't study for 0 or 1.5 hours), but she won't study more than 11 hours in any 7-day period. Prove that there must exist some period of consecutive days during which Jessica studies exactly 20 hours.
Click here to see answer by math_helper(2461)  |
Question 1119745: Three of nine astronauts must be selected for a mission. One will be the captain, one will be the navigator, and one will perform scientific experiments. Assuming each of the nine astronauts can perform any of the tasks, in how many ways can a three-person crew be selected so that each person has a different assignment?
Click here to see answer by mahsiiiii(1) |
Question 1119745: Three of nine astronauts must be selected for a mission. One will be the captain, one will be the navigator, and one will perform scientific experiments. Assuming each of the nine astronauts can perform any of the tasks, in how many ways can a three-person crew be selected so that each person has a different assignment?
Click here to see answer by Shin123(626)  |
Question 1119744: (60 points) On a table in a doctors office are five Motor Trend magazines, six Parenting magazines, and three Sports Illustrated magazines. If a patient randomly selects three magazines, determine the probability that
a. three Motor Trend magazines are selected.
b. two Parenting magazines and one Sports Illustrated magazine are selected.
c. no Parenting magazine is selected.
d. at least one Parenting magazine is selected
Click here to see answer by ikleyn(52786)  |
Question 1123139: In a sample of 80 adults, 28 said that they would buy a car from a friend. Three adults are selected at random without replacement. Find the probability that none of the three would buy a car from a friend.
Click here to see answer by ikleyn(52786) |
Question 1129474: Question about probability.
If a question asks, what is the number of sequences of heads or tails if a coin is flipped 7 times, what is it asking for? I am confused if this is permutation or combination.
Am I to find the different ways each flip could go if done 7 times and then add the different sets together?
i.e.
HTTTTTT+HHTTTTT etc.
Thank you!
Click here to see answer by ikleyn(52786) |
Question 1129474: Question about probability.
If a question asks, what is the number of sequences of heads or tails if a coin is flipped 7 times, what is it asking for? I am confused if this is permutation or combination.
Am I to find the different ways each flip could go if done 7 times and then add the different sets together?
i.e.
HTTTTTT+HHTTTTT etc.
Thank you!
Click here to see answer by solver91311(24713)  |
Question 1129979: I have a question regarding probability distribution.
If given a few choices, and after adding them up:
Choice 1 equaled 1.1
Choice 2 equaled 1.1
Choice 3 equaled 1.0
Choice 4 equaled 1.0
If I understand this correctly,a probability must be a number between 0 and 1, inclusive. For probability distribution, the sum of the probabilities must be 1.
With that in mind, Choice 3: 0.5-0.2+0.3+0.4 would not be correct because one of the numbers is negative?
Where,
Choice 4: 0.1+0.6+0+0.3would be a solution because it falls within all specified parameters?
Am I interpreting this correctly?
Thank you!
Click here to see answer by ikleyn(52786) |
Question 1130886: I've been trying to figure this out for quite a quite now, but cant seem to get the solution correct.
Using probability distribution I need to figure out the following:
what is the probability of getting three questions on a four question (true or false) test correct by guessing?
I'm looking for (p) the probability of 3 0ut of 4. I believable it is .5, but that's just a guess. I can't figure out how to calculate this.
I know it's a 4 question test with 8 different t/f possibilities, but I can't figure out how to get (p) using probability distribution.
Thank you
Click here to see answer by ikleyn(52786) |
Question 1131821: If one is only given a sample mean and sample standard deviation, is it possible to calculate the percentage of data that falls within one standard deviation of the mean? If it is possible, how or what formula is used?
I've looked all over, and cannot figure out how it can be done.
Any guidance would be very helpful.
Thank you
Click here to see answer by Theo(13342) |
Question 1131810: Use the normal curve to make the estimates requested.
The census from a certain year revealed that 22.8% of the U.S. veteran population were disabled. In a random selection of 100 veterans, estimate the probability that 30 to 40 of them were disabled. (Round your answer to three decimal places.)
Click here to see answer by Boreal(15235) |
Question 1134020: a box of 80 candles consist of 30 defective and 50 non defective candles.If 10 of these candles are selected randomly what is the probability of all will be defective,6 will be non defective,all will be non defective?
Click here to see answer by Glaviolette(140)  |
Question 1134979: Assume that when adults with smartphones are randomly selected, 42% use them
in meetings or classes. If 8 adult smartphone users are randomly selected,
find the probability that at least 5 of them use their smartphones in
meetings or classes.
Click here to see answer by AnlytcPhil(1806)  |
Question 1135587: The manager of a hotel room report that the mean number of rooms rented out per night is at least 212 based on his observation for the past several months. One of the corporate official observed an over estimation, where a sample of 150 nights produce a mean of 201.3 rooms and a standard deviation of 45.5 rooms.. if the result suggest the manager has inflated his report he will be given a warning, at 5% level. what is the managers Fate?
Click here to see answer by Theo(13342) |
Question 1136577: For a population that has a standard deviation of 20, determine the standard deviation of the distribution of means for samples of size of 4
For this problem do I use the formula:
𝜎
___
√𝑛
where the answer is 20/2= 10??
Please clarify if this is correct. Thank you in advance
Click here to see answer by Theo(13342) |
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