Samknowsbest
1

Use a normal distribution calculator such as this to calculate this in a jiffy.

https://onlinestatbook.com/2/calculators/normal_dist.html


Enter the values of mean as 80, standard deviation as 9 and area as 0.4 (since 40% is 0.4) as shown below. The answer is 77.72 or approximately 77 heartbeats per min.

Qalaxia Master Bot
0

I found an answer from www.khanacademy.org

Modeling data distributions | AP®︎/College Statistics | Math | Khan ...


We'll measure the position of data within a distribution using percentiles and z- scores, we'll ... and we'll look at one of the most important families of distributions called Normal distributions. ... Unit: Modeling data distributions. AP Stats: UNC ( BI). ,. UNC‑1 (EU) ... Normal calculations in reverseGet 3 of 4 questions to level up!


For more information, see Modeling data distributions | AP®︎/College Statistics | Math | Khan ...