Answer:
the answer is -16 x ^3 + 116 x ^2 -96 x -144
Answer:
The proportion of students whose height are lower than Darnell's height is 71.57%
Step-by-step explanation:
The complete question is:
A set of middle school student heights are normally distributed with a mean of 150 centimeters and a standard deviation of 20 centimeters. Darnel is a middle school student with a height of 161.4cm.
What proportion of proportion of students height are lower than Darnell's height.
Answer:
We first calculate the z-score corresponding to Darnell's height using:

We substitute x=161.4 ,
, and
to get:

From the normal distribution table, we read 0.5 under 7.
The corresponding area is 0.7157
Therefore the proportion of students whose height are lower than Darnell's height is 71.57%
Answer:
×=18+25=9²
Step-by-step explanation:
Hope this helps
Answer:
P(A) = 44.44%
P(B) = 50%
P(B|A) = 37.5%
P(B|A) different from P(B).
A and B are independent.
Step-by-step explanation:
If we have a total of 180 students, and 80 of them have a Playstation, we have that P(A) = 80/180 = 0.4444 = 44.44%
If we have 90 students that have a Xbox, we have that P(B) = 90/180 = 0.5 = 50%
If we have 30 students that have both consoles, we have that P(A and B) = 30/180 = 0.1667 = 16.67%
To find P(B|A), we will find for a student that has an Xbox inside the group of students that has a Playstation, that is, we have 30 students in a total of 80 students, so P(B|A) = 30/80 = 0.375 = 37.5%
P(B|A) is different from P(B), the first is 37.5% and the second is 50%, so events A and B are independent events.