Answer:
P(Y ≥ 15) = 0.763
Step-by-step explanation:
Given that:
Mean =135
standard deviation = 12
sample size n = 50
sample mean = 140
Suppose X is the random variable that follows a normal distribution which represents the weekly supermarket expenses
Then,
The probability that X is greater than 140 is :
P(X>140) = 1 - P(X ≤ 140)
From z tables,
Similarly, let consider Y to be the variable that follows a binomial distribution of the no of household whose expense is greater than $140
Then;
∴
P(Y ≥ 15) = 1- P(Y< 15)
P(Y ≥ 15) = 1 - ( P(Y=0) + P(Y=1) + P(Y=2) + ... + P(Y=14) )
P(Y ≥ 15) = 0.763
9 9x5=45
5,10,15,20,25,30,35,40,45
9
Answer:
x=-32/29
Step-by-step explanation:
3x+4y=36 Equation 1
-5x+3y=35 Equation 2
Multiplying equation 1 with 3 (value before y in equation 2) and equation 2 with 4 (value before y in equation 1) we obtain equations 3 and 4 as follows
9x+12=108 equation 3
-20x+12y=140 equation 4
Subtracting equation 3 from equation 4 we obtain
-29x=32
x=-32/29
To find the value of y, we substitute the value of x into equation 2 as initially given in the equation
-5(-32/29)=35-3y
-5(-32/29)-35=-3y