Answer:
(x, y) = (-3, -6)
Step-by-step explanation:
The second equation can be used to write an expression for y:
... -5x -21 = y . . . . . . . add y-21 to both sides
This expression can be substituted for y in the first equation:
... 6 = -4x +(-5x -21)
... 27 = -9x . . . . . add 21, collect terms
... -3 = x . . . . . . . divide by -9
Using this value of x in the expression for y, we find ...
... -5(-3) -21 = y = -6
The solution is x = -3, y = -6.
Using the <u>normal distribution and the central limit theorem</u>, it is found that there is a 0.1635 = 16.35% probability of a sample result with 68% or fewer returns prior to the third day.
In a normal distribution with mean and standard deviation
, the z-score of a measure X is given by:
In this problem:
The <u>mean and the standard error</u> are given by:
The probability is the <u>p-value of Z when X = 0.68</u>, hence:
By the Central Limit Theorem
has a p-value of 0.1635.
0.1635 = 16.35% probability of a sample result with 68% or fewer returns prior to the third day.
A similar problem is given at brainly.com/question/25735688