Stats Definition and 227 Threads

Ok, This problem sounds really easy, but I think I am doing something wrong. Question : If the mean time between some random event occurring is 6 months, what is the probablity that in one year the event does not happen. I think its like flipping a coin. There is a 0.5 chance of the...

Does anyone have any stats on how often airliners land themselves? I googled a little and couldn't find any.

Okay so I did this problem and got it wrong but I get one more chance to get it right. I tried using Binomial Dist to solve it but I failed. 30% of all M&Ms are brown. If 7 M&Ms are randomly selected, what is the probability that at most 1 is brown? I thought I would use 0 and 1 but I...

Hi Everyone, I am new to the forum and really need so help before I have a test tomorrow. I have been going over my book and working through the problems but I am stuck on this problem. Would someone please help me? thank you very much for your time From a study average height of men...

it seems like all the major problems in math/stats are only in math. why is that? is it because stats is a relatively new field of study (got started ~50yrs ago i think by florence nightingale?), not counting gauss' central limit theorem? or is it because statisticians only work with data...

Hello, my book has this question, and no examples (very) similar to it, so I am wondering if I did it correct :smile: --------- The following circuit operates if and only if there is a path of functional devices from left to right. The probability that deach device functions is as shown...

Hello I am taking 1st year stats at university, and I have lab questions I am supposed to answer. I am VERY confused. My data set is: 53, 33, 25, 63,26, 64, 32, 21, 45, 64, 38 I calculated the mean:42.182 the sample variance:272.147 The range:43 The percentile rank of the data value 45...

statistics and probability

http://arxiv.org/Stats/ they plot the average monthly posting rate for preprints in several categories: hep, astro, mathphys, condensedmatter the solid bar is the actual posting in that category, the blank part is crossposting from other categories so looking at the solid blue, for...

1 out of 5 italians speak english. 1 out of 5 people in italy are tourists. 1 out 2 tourists speaks english. You meet a english-speaking person in italy, what is the probability that this person is italian. The way I see the "population": P(I) = \frac{2}{10} are italians who speaks english...

hello, I'm a newcomer here :smile: i am taking statistics 1001 and am having a horrible time with this weeks homework. it basically has to do with regression. unfortunately my teacher barely speaks english and it was especially hard to understand her this week (is she speaking about z-scores -...

hi, need some help on these stats problems that i am confused about? 1. market research in a particular city indicated that during a week 18% of all adults watched a television program oriented to business and financial issues, 12% read a publication oriented to these issues, and 10% do...

QUESTION3: Alexander Da Costa & Priyanka Kapadia Petroleum, plans to drill 5 exploratory wells. Jenny Wong & Danny Tieu Consulting geologists give the probability that a well results in a discovery as 0.20 for the first 3 wells. If there is a discovery in the first 3 wells the geologist's...

Its deciding which Stats method to use that the problem... Hello, i hope you don't mind a biologist interloping on your boards :) I have a statistics problem that i could do with some help with if anyone can (please!). I'm taking 2 8ml samples from a volume of 200mls. Distributed evenly...

In the early 1990s, Fuji Photo Film, USA, joined forces with four of its rivals to create the Advanced Photo System (APS), which is hailed as the first major development in the film industry since 35 - millimeter technology was introduced. In February 1996, the new 24 millimeter system...

first of all (just so people don't try to call me a hypocrite) if I saw a list like this showing such scandalous (to put it mildly) stats on Canada I would be mortified. (actually the homeless & poverty we've got here is pathetic given Canada's wealth, lack of enemies, etc) but look at what what...

help please: "Within three months, Colgate grabbed the number one market share for toothpaste. Ten months later, 21% of all U.S. households had purchased Total (a product of Colgate) for the first time. During this same period, 43% of those who initially tried Total purchased it again...

this page of stats is an update of one that Alejandro flagged some months back. It has a different URL now, and it continues the graphs up to December 04. http://arxiv.org/Stats/ Dont expect to see anything about quantum gravity or stringy research explicitly. this is only graphing the...

If the regression equation is y=2.3-1(x) and r^2 = 0.78, what is the value of the coefficient of correlation? my answer was 0.88 and i got it wrong, is it -0.88 because of the negative slope in the equation? please help fast.. thnx

from callen, equation 16.10 reads Z = sum(e^-BE) the text later says that F = -kT ln Z, and states that it gives the helmholtz potential as a function of B, V, N where B = 1/kT my question is, what part of this relationship characterizes the volume?

I'm working on a question which requires you to understand the difference between Independence and disjoint events. The question is: Suppose 24% of a population have 4 years of college, and 15% are laborers/workers. From this, can you conclude that 0.24 x 0.15 = 0.036=3.6% of the population are...

Destructive SAmpling, in which the test to determine whether an item is defective destroys the item, is generally exensive, and the high costs involved often prohibit large sample sizes. For exampl, suppose the National Highway TRaffic SAfety Administrator wishes to detrmine the proportion of...

1. If a school offers 3200 separate courses and a survey of these courses determines that the class size is 50 with a standard deviation of 2, what would one expect for the average and standard deviation of a subset of 50 of these classes selected randomly? 2. In a survey to estimate the...

Hi! I'm new to this forum. I took some stats in University but that was so long ago that I don't remember much. I'm trying to figure out how big of a sample size I need to generate some stats for the company I work for. I'm not sure what info is needed but if anyone is interested in helping...

i've got a stats issue that i'd love some ruling on if anyone cares to help.. i've got a population of hospital patients with a diagnosis of anemia admitted in 2004 - n=191 the rate at which these 191 catch the flu while in stay is 39% (or 75 of them) during that same time (2004) 90 of...

A star was measured to have an apparent magnitude m=16 with S/N=10 integrated over a minute. What is the uncertainty in the measurement? signal=flux*area*time noise=sqrt(signal)=sqrt(fAt) So, S/N=sqrt(fAt) How can I find fA? m=-2.5logfAt+K 16=-2.5log(fAt)+K Hoping that K is arbitrary...

What to do when you have some extra time? Play with some numbers ofcourse :) I downloaded all the birthdays registered in PF and did a few spreadsheet calculations: In total there were 592 entries, of which one was of a 3 year old and another of a 101 year old person.. those were not...