Let m be a random variable representing the amounts of nicotine in a certain brand of cigarette. Given that x is normally distributed, we would calculate the z score by applying the formula given below
[tex]z\text{ = }\frac{x\text{ - }\mu}{\frac{\sigma}{\sqrt[]{n}}}[/tex]
where
x = sample mean
σ = population mean
n = sample size
μ = population mean
From the information given,
μ = 0.316
x = 0.823
n = 41
σ = 0.902
Bu substituting these values into the formula,
[tex]\begin{gathered} z\text{ = }\frac{0.823\text{ - 0.902}}{\frac{0.316}{\sqrt[]{41}}} \\ z\text{ = - 1.6}01 \end{gathered}[/tex]
We want to find P(m < 0.823)
We would do this by finding the probability value corresponding to a z score of - 1.601 from the standard normal distribution table. From the table,
P(m < 0.823) = 0.054