Final answer:
To find the probability of someone having a systolic blood pressure reading greater than 145, calculate the z-score using the given mean and standard deviation, and then find the corresponding probability using a standard normal distribution table or calculator. The probability is approximately 0.08%.
Step-by-step explanation:
To find the probability that a randomly selected person has a systolic blood pressure reading greater than 145, we need to calculate the z-score and then use a standard normal distribution table or calculator.
The z-score can be found using the formula: z = (x - μ) / σ, where x is the value we want to find the probability for, μ is the mean, and σ is the standard deviation.
Using the given values, the z-score for 145 can be calculated as: z = (145 - 120) / 8 = 3.125.
The probability of getting a z-score of 3.125 or higher can be found using a standard normal distribution table or calculator. In this case, the probability is approximately 0.0008, or 0.08%.