You can check khan academy for help I’m sorry I don’t exactly know :(
X=13; do you need the work? Also for future reference symbolab.com is where I get all my answers.
Same strategy as before: transform <em>X</em> ∼ Normal(76.0, 12.5) to <em>Z</em> ∼ Normal(0, 1) via
<em>Z</em> = (<em>X</em> - <em>µ</em>) / <em>σ</em> ↔ <em>X</em> = <em>µ</em> + <em>σ</em> <em>Z</em>
where <em>µ</em> is the mean and <em>σ</em> is the standard deviation of <em>X</em>.
P(<em>X</em> < 79) = P((<em>X</em> - 76.0) / 12.5 < (79 - 76.0) / 12.5)
… = P(<em>Z</em> < 0.24)
… ≈ 0.5948
2.1 is already in a decimal form.
Hope I helped!
It's the inverse operation of squaring that number. It's an odd definition to explain lol
