Answer: the probability that fewer than 100 in a random sample of 818 men are bald is 0.9830
Step-by-step explanation:
Given that;
p = 10% = 0.1
so let q = 1 - p = 1 - 0.1 = 0.9
n = 818
μ = np = 818 × 0.1 = 81.8
α = √(npq) = √( 818 × 0.1 × 0.9 ) = √73.62 = 8.58
Now to find P( x < 100)
we say;
Z = (X-μ / α) = ((100-81.8) / 8.58) = 18.2 / 8.58 = 2.12
P(x<100) = P(z < 2.12)
from z-score table
P(z < 2.12) = 0.9830
Therefore the probability that fewer than 100 in a random sample of 818 men are bald is 0.9830
For the levels of qualitative, the variable called dummy variables is used in the multiple regression method.
According to the statement
we have given that the by which method we use the different levels of a qualitative independent variable and we have to explain about it.
So, For his purpose, we know that the
A dummy variable is a variable that takes values of 0 and 1, where the values indicate the presence or absence of something.
And in the multiple regression method there are a lot of different variables which are used for a qualitative and for this a variable is used which is called the dummy variables.
By this variables we show the analysis between the given data. it gives the output in the 0 and 1 numbers.
So, For the levels of qualitative, the variable called dummy variables is used in the multiple regression method.
Learn more about the Dummy variables here
brainly.com/question/17177646
#SPJ4
Answer:
<u>The number of pens = 120 and the number of pencils = 200</u>
Step-by-step explanation:
Let the number of pens x, and the number of pencils is y
the cost of one pen $1, and the cost of one pencil $0.5
The cost of the whole purchase was $220
1 * x + 0.5 * y = 220
x + 0.5 y = 220 ⇒ eq.(1)
there were 80 more pencils than pens
y - x = 80 ⇒ eq.(2)
from eq.(2) x = y - 80
By substitution with x from the last equation at eq.(1)
∴ (y - 80) + 0.5 y = 220
1.5y = 220 + 80 = 300
y = 300/1.5 = 200
x = y - 80 = 200 - 80 = 120
<u>So, the number of pens = 120 and the number of pencils = 200</u>
