Answer:
4.4% of the population with IQ between 120 and 125.
Step-by-step explanation:
We are given the following information in the question:
Mean, μ = 100
Standard Deviation, σ = 15
We are given that the distribution of IQ scores is a bell shaped distribution that is a normal distribution.
a) Let X be a person's IQ score.
Then, density functions for IQ scores is given by:
b) P(population with IQ between 120 and 125.)
Formula:
Answer:
The probability that randomly selected road will be at least 25.8 cm long will be 48%.
Step-by-step explanation:
Given: uniform distribution with min and max values of 18 and 33 respectively.
To find : probability density for upper cumulative frequency i.e 25.8 at least means x25.8 upto 33 cm i.e the maximum limit of function.
Solution:
we have by definition , of uniform distribution
we get , probability density function defines as :
<em>F(x,a,b)= </em><em> </em>
=1/(33-18)=1/15=0.0667.
this is probability density function.
here the x=25.8 , a=18 and b=33
for lower cumulative frequency it defines as ;
P(x,a,b)= =25.8-18/33-18=0.52
for upper cumulative frequency it defines as ;
Q(x,a,b)=b-x/b-a=33-25.8/33-18=0.48
here at least 25.8 cm probability means it should be greater than a value(18cm) hence it is provided by the upper cumulative frequency
i.e. Q(x,a,b)=0.48
The probability that randomly selected road will be at least 25.8 cm long will be 48%.