Complete Question
A population has a mean of 25, a median of 24, and a mode of 26. The standard deviation is 5. The value of the 16th percentile is _______. The range for the middle 3 standard deviation is _______.
Answer:
The value of the 16th percentile is
![x = 20](https://img.qammunity.org/2021/formulas/mathematics/middle-school/q1i7dn6ljir99re9fojnl8jwj6cyxusu19.png)
The range for the middle 3 standard deviation is
![10 \to 40](https://img.qammunity.org/2021/formulas/mathematics/college/evnmoqhejrkv4okxuhokrtz9k673ysreuq.png)
Explanation:
From the question we are told that
The mean is
![\mu = 25](https://img.qammunity.org/2021/formulas/mathematics/college/duc4hxmmcryw3ufk6s2akcrvfpsy7im19l.png)
The median is
![m = 24](https://img.qammunity.org/2021/formulas/mathematics/college/ketx76m596wsd5x6vempp72xfht5sozy47.png)
The mode is
![n = 26](https://img.qammunity.org/2021/formulas/mathematics/college/exlb3s4z9a4icoeu1s5gpydy7m8o1tqnen.png)
The standard deviation is
![\sigma = 5](https://img.qammunity.org/2021/formulas/mathematics/college/3oonph6nj63i9ucxhy00d3iymsyiljq39m.png)
Generally the 16th percentile is mathematically represented as
![P(x)= P((X - \mu )/( \sigma ) \le (x- 25 )/(5) ) = 0.16[/te</p><p>Generally [tex](X - \mu)/(\sigma ) = Z(The \ standardized \ value \ of \ X )](https://img.qammunity.org/2021/formulas/mathematics/college/jlalo0lft1rd9lomebsq7grx8quf2ivw2i.png)
So
![P(x) = P(Z \le ( x - 25)/(5) ) = 0.16](https://img.qammunity.org/2021/formulas/mathematics/college/czmm06trf4ph8d1pf3t4pjfk13hhw4bxfv.png)
Now from the normal distribution table the z-score of 0.16 is
z = -1
![P(x) = P(Z \le ( x - 25)/(5) ) = P(Z \le -1 )](https://img.qammunity.org/2021/formulas/mathematics/college/nb06ope9jts24vripbsioa5jiik0ek35v3.png)
=>
![(x- 25)/(5) = -1](https://img.qammunity.org/2021/formulas/mathematics/college/zksag2butospbuaxpo67pstpb1z37to6zh.png)
=>
![x- 25 = -5](https://img.qammunity.org/2021/formulas/mathematics/college/k9cph20uq2z2dacw418l2cae0y6csky2oq.png)
=>
![x = 25-5](https://img.qammunity.org/2021/formulas/mathematics/college/q29zvm8k7c6gt5wu4fisc13kvc9yxeobcp.png)
=>
![x = 20](https://img.qammunity.org/2021/formulas/mathematics/middle-school/q1i7dn6ljir99re9fojnl8jwj6cyxusu19.png)
The range for the middle 3 standard deviation is mathematically represented
![\mu - 3\sigma \to \mu + 3\sigma](https://img.qammunity.org/2021/formulas/mathematics/college/5vqgrmsnq5rzf34dirb47jy0j9d1hfyys4.png)
![25 - 3(5 ) \to 25 + 3(5 )](https://img.qammunity.org/2021/formulas/mathematics/college/7o8elydrxhip62tn90qd1l63p64l4cmd2s.png)
![10 \to 40](https://img.qammunity.org/2021/formulas/mathematics/college/evnmoqhejrkv4okxuhokrtz9k673ysreuq.png)