Final answer:
The city temperature when its z-score is 1.21 is approximately 74.813 ºF.
Step-by-step explanation:
To find the city temperature when its z-score is 1.21, we can use the formula:
x = μ + z * σ
where x is the city temperature, μ is the mean temperature, z is the z-score, and σ is the standard deviation.
Given that the mean temperature is 69.5 ºF, the z-score is 1.21, and the standard deviation is 4.3 ºF, we can substitute these values into the formula:
x = 69.5 + 1.21 * 4.3 = 74.813 ºF
Therefore, the city temperature when its z-score is 1.21 is approximately 74.813 ºF.