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:
a=28
Step-by-step explanation:
use inverse operations
Answer:
length=45 m (2 sides = 90m)
Step-by-step explanation:
5x +3x=144
8x=144
x=18 (each of the 8 parts of 144 measure 18m)
5(18) + 3(18)=144
90 +54=144
90/2=45 (1 length side)
54/2=27 (1 width side)
The rectangle= 45+45 +27+27 = 144
It took him 9.92 hours to complete the journey.
Step-by-step explanation:
Given,
Distance traveled = 50 miles
Distance traveled on horse = 
Distance traveled on foot = 25 miles
Speed while riding = 9 miles per hour
Distance = Speed * Time
Time while riding = 
Time while riding = 
Speed while waling = 3.5 miles
Time = 
Total time = 2.78+7.14 = 9.92 hours
It took him 9.92 hours to complete the journey.
Keywords: speed, distance
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