title: How to calculate probability in normal distribution with R
body: <p>There is a variable <strong>M</strong> with normal distribution N(μ, σ), where μ=100 and σ = 10.</p>
  
  <p>Find the probability P{|M-80|≥ 11}?</p>
  
  <p>What I did using R was:</p>
  
  <ol>
  <li>P{|M-80|≥ 11} = P{|M|≥ 11 + 80} = P{|M|≥ 91} </li>
  <li>pnorm(91, mean=100, sd=10, lower.tail = FALSE)</li>
  </ol>
  
  <p>But it's incorrect!,  please can you tell me what's the correct way?</p>