Re: The figure above shows the standard normal distribution with mean 0 an
[#permalink]
16 Sep 2023, 23:36
OE
If we consider normal distribution curve given in the question,
We know value at 20th percentile would lie in between ‘𝑀 – 𝐷’ and ‘𝑀’.
Where 𝑀 is mean and 𝐷 is standard deviation.
It is given that, value is at 20th percentile is 135
So, we can say ‘𝑀 – 𝐷’ < 𝑥 < 𝑀
𝑀 – 10 < 135 < 𝑀
𝑀 – 10 < 135 and 135 < 𝑀
𝑀 < 145 and 𝑀 > 135
135 < 𝑀 < 145
Out of the available answer choices, we can say that
𝑀 = 140