I am asking to use central limit theorem to solve this quesion. In an election between two candidates, A and B, one million individuals cast their vote.  Among these, 2000 know candidate A from her election campaign and vote unanimously for her. The remaining 998000 voters are undecided and make their decision independently of each other by flipping a fair coin.  Approximate the probability pA that candidate A wins up to 3 significant figures. I got my mean = np = (1000000-2000)  * 0.5 = 499000, my sd =$\sqrt {np*(1-p)}$= $\sqrt {998000*0.5*(1-0.5)}$, then apply CLT, my new sd = $\frac{sd}{\sqrt{998000}}$, and X = $\frac{1000000}{2}$+1-2000 = 498001. Then apply normal distribution. Am I right?
I am asked to solve the following question using central limit theorem. In an election between two candidates, A and B, one million individuals cast theirvote. Among these, 2000 know candidate A from her election campaign and vote unanimously for her.The remaining 998000 voters are undecided and make their decision independently of each other byflipping a fair coin.Approximate the probability pA that candidate A wins up to 3 significant figures.  It's easy to solve directly. PA = $\frac{0.5(10000-2000)+2000}{10000}$ = 0.501. However, I am quite confused about how to solve this problem by central limit theorem.
Should I use the past tense with did? For example, I was to say:     The important question is: Did they knew what it means or not?   Or should I say:     The important question is: Did they know what it means or not?   In other words: Should I use past tense with did?  I looked at this:    but it didn't really answer my question. Two monitors when only having one in 13.10 I just did a fresh install of Ubuntu 13.10 64bit, and it says that I have 2 monitors, when I actually only have one    I have a Dell XPS 15 with Nvidia graphics card if that helps in anyway What is the difference between DX format and FX format lenses, and which to choose for what purpose? What is the difference between DX format and FX format lenses, and which to choose for what purpose?  What are the pros and cons of both? If $x_1=5$, $x_{n+1}=x_n^2-2$, find $\lim x_{n+1}/(x_1\cdots x_n)$ Recently I've noticed more and more sign-in / sign-up workflows defaulting to the sign-up option first and providing a minimal "Sign-In / Login" action somewhere else on the page. What's the reason behind this practice?  Examples where I've seen this recently: Beamer: Vertical alignment of multi-column ToC I've seen many posts regarding a combinatorial proof of the following question. But for a non-combinatorial proof would the following method work? Also... is this the easiest way to arrive at a proof? It seems to be rather verbose.  Show the formula $k {n\choose k} = n {n-1 \choose k-1}$ is true for all integers $n,k$ with $0\le k \le n$.  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After using gdalwarp to project and align-to-grid (via -tap) a number of rasters I noticed that the output rasters were significantly larger than the original rasters. A fairly thorough web search turned up :  Frank Warmerdam explained the reason: &quot;On careful review, the difference in the file in question is because gdal_translate uses the TIFFWriteScanline() interface to write the output file from within GTiffDataset::CreateCopy?(), and this only writes as much of the final 'strip' of the file as is required to complete image area. But gdalwarp goes through the blockio interface which writes the complete final strip, even the portion that falls off the end of the file.&quot;  This Trac issue is ~7 years old, however, and I know some changes to the GDAL utilities, including gdalwarp have been made since. I'd like to know if the above reasoning still holds and if the file size inflation I'm seeing is &quot;normal.&quot; The word &quot;normal&quot; here might be taken to mean unsurprising or expected but, more importantly: is there anything that can be done to mitigate the effects i.e. reduce the output raster file size? Below is a table of the file size inflation I'm experiencing. Input File Size (bytes)     Output File Size (bytes)    Inflation 1437380431                  1698334217                   18% 1428001178                  1698334433                   19%   41683165                   137036637                  228%  The input TIFF files were created in ArcGIS and thus have external Worldfiles, XML and DBF files but these do not make up the difference in file size. Here is a sample gdalwarp call as I've used it in all of these cases; the actual execution was handled by a Python subprocess (subprocess.Popen): $ gdalwarp -tap -tr 30 30 -t_srs &quot;+proj=aea +lat_1=20 +lat_2=60 +lat_0=40 +lon_0=-96 +x_0=0 +y_0=0 +ellps=GRS80 +datum=NAD83 +units=m +no_defs&quot; -co &quot;COMPRESS=LZW&quot; input_file.tif output_file.tif  I understand that in rare cases compression makes a larger file, but the effect is the same without the LZW compression. The ratios in the table are with LZW compression. "Access denied" when trying to end a process on Windows 8 When to use ' (or quote) in Lisp? After making it through the major parts of an introductory Lisp book, I still couldn't understand what the special operator (quote) (or equivalent ') function does, yet this has been all over Lisp code that I've seen.    What does it do? Regular Expression to match valid dates I'm trying to write a regular expression that validates a date.  The regex needs to match the following   M/D/YYYY MM/DD/YYYY Single digit months can start with a leading zero (eg: 03/12/2008) Single digit days can start with a leading zero (eg: 3/02/2008) CANNOT include February 30 or February 31 (eg: 2/31/2008)   So far I have   ^(([1-9]|1[012])[-/.]([1-9]|[12][0-9]|3[01])[-/.](19|20)\d\d)|((1[012]|0[1-9])(3[01]|2\d|1\d|0[1-9])(19|20)\d\d)|((1[012]|0[1-9])[-/.](3[01]|2\d|1\d|0[1-9])[-/.](19|20)\d\d)$   This matches properly EXCEPT it still includes 2/30/2008 &amp; 2/31/2008.  Does anyone have a better suggestion?  Edit: I found  on RegExLib  ^((((0[13578])|([13578])|(1[02]))[\/](([1-9])|([0-2][0-9])|(3[01])))|(((0[469])|([469])|(11))[\/](([1-9])|([0-2][0-9])|(30)))|((2|02)[\/](([1-9])|([0-2][0-9]))))[\/]\d{4}$|^\d{4}$   It matches all valid months that follow the MM/DD/YYYY format.  Thanks everyone for the help. Preview on the right please, optionally? How to limit execution time of a function call? 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