{"id":211327,"date":"2025-05-03T16:47:47","date_gmt":"2025-05-03T16:47:47","guid":{"rendered":"https:\/\/learnexams.com\/blog\/?p=211327"},"modified":"2025-05-03T16:47:50","modified_gmt":"2025-05-03T16:47:50","slug":"the-probability-a-gambler-will-win-money-on-a-certain-slot-machine-is-2-5","status":"publish","type":"post","link":"https:\/\/www.learnexams.com\/blog\/2025\/05\/03\/the-probability-a-gambler-will-win-money-on-a-certain-slot-machine-is-2-5\/","title":{"rendered":"The probability a gambler will win money on a certain slot machine is 2.5%"},"content":{"rendered":"\n<p>The probability a gambler will win money on a certain slot machine is 2.5%. Determine the probability that a gambler will win at least 5 times if they play 100 times.<\/p>\n\n\n\n<p><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-ast-global-color-6-color\"><strong>The correct answer and explanation is :<\/strong><\/mark><\/p>\n\n\n\n<p>To solve this problem, we are dealing with a <strong>binomial distribution<\/strong>. In a binomial distribution, there are a fixed number of independent trials (in this case, 100 plays), each with two possible outcomes (win or not win), and a constant probability of success (win) in each trial.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Step 1: Defining the parameters of the binomial distribution<\/h3>\n\n\n\n<p>We have the following parameters:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>n = 100<\/strong> (the number of trials, or the number of times the gambler plays the slot machine).<\/li>\n\n\n\n<li><strong>p = 0.025<\/strong> (the probability of winning in a single trial, as given by 2.5%).<\/li>\n\n\n\n<li>We are asked to determine the probability of winning <strong>at least 5 times<\/strong>, meaning we want to find $P(X \\geq 5)$, where $X$ is the number of wins in 100 plays.<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">Step 2: Applying the binomial distribution<\/h3>\n\n\n\n<p>The number of wins $X$ follows a <strong>binomial distribution<\/strong>:<\/p>\n\n\n\n<p>$$<br>X \\sim B(n=100, p=0.025)<br>$$<\/p>\n\n\n\n<p>The probability mass function (PMF) for a binomial distribution is given by:<\/p>\n\n\n\n<p>$$<br>P(X = k) = \\binom{n}{k} p^k (1-p)^{n-k}<br>$$<\/p>\n\n\n\n<p>where $\\binom{n}{k}$ is the binomial coefficient, and $k$ is the number of successes (wins).<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Step 3: Calculating the probability of winning at least 5 times<\/h3>\n\n\n\n<p>The problem asks for $P(X \\geq 5)$, which is the probability of having 5 or more wins. We can calculate this by finding the complement, which is the probability of having fewer than 5 wins, and subtracting it from 1:<\/p>\n\n\n\n<p>$$<br>P(X \\geq 5) = 1 &#8211; P(X &lt; 5) = 1 &#8211; (P(X = 0) + P(X = 1) + P(X = 2) + P(X = 3) + P(X = 4))<br>$$<\/p>\n\n\n\n<p>This requires calculating the individual probabilities for $P(X = 0), P(X = 1), P(X = 2), P(X = 3),$ and $P(X = 4)$, then summing them up and subtracting from 1.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Step 4: Using a normal approximation<\/h3>\n\n\n\n<p>For large $n$, a binomial distribution can be approximated by a normal distribution. Since $n$ is large, we can use the normal approximation to the binomial distribution:<\/p>\n\n\n\n<p>$$<br>X \\sim N(\\mu = np, \\sigma^2 = np(1-p))<br>$$<\/p>\n\n\n\n<p>where:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>$\\mu = np = 100 \\times 0.025 = 2.5$<\/li>\n\n\n\n<li>$\\sigma^2 = np(1-p) = 100 \\times 0.025 \\times 0.975 = 2.4375$<\/li>\n\n\n\n<li>$\\sigma \\approx 1.56$ (the standard deviation)<\/li>\n<\/ul>\n\n\n\n<p>Using the normal approximation, we convert the discrete probability to a continuous probability using a continuity correction. We want $P(X \\geq 5)$, which is equivalent to $P(X \\geq 4.5)$ in the normal distribution.<\/p>\n\n\n\n<p>We can standardize this to a z-score:<\/p>\n\n\n\n<p>$$<br>z = \\frac{X &#8211; \\mu}{\\sigma} = \\frac{4.5 &#8211; 2.5}{1.56} \\approx 1.28<br>$$<\/p>\n\n\n\n<p>Using standard normal tables or a calculator, we find the probability corresponding to a z-score of 1.28, which is approximately 0.8997.<\/p>\n\n\n\n<p>Thus:<\/p>\n\n\n\n<p>$$<br>P(X \\geq 5) \\approx 1 &#8211; 0.8997 = 0.1003<br>$$<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Step 5: Conclusion<\/h3>\n\n\n\n<p>The probability that a gambler will win at least 5 times if they play 100 times is approximately <strong>0.1003<\/strong>, or <strong>10.03%<\/strong>. This means there is about a 10% chance the gambler will win at least 5 times after 100 plays, based on the given probability of winning in each play.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>The probability a gambler will win money on a certain slot machine is 2.5%. Determine the probability that a gambler will win at least 5 times if they play 100 times. The correct answer and explanation is : To solve this problem, we are dealing with a binomial distribution. In a binomial distribution, there are [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"site-sidebar-layout":"default","site-content-layout":"","ast-site-content-layout":"default","site-content-style":"default","site-sidebar-style":"default","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","ast-disable-related-posts":"","theme-transparent-header-meta":"","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"default","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"ast-content-background-meta":{"desktop":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"footnotes":""},"categories":[25],"tags":[],"class_list":["post-211327","post","type-post","status-publish","format-standard","hentry","category-exams-certification"],"_links":{"self":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/211327","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/comments?post=211327"}],"version-history":[{"count":0,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/211327\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/media?parent=211327"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/categories?post=211327"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/tags?post=211327"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}