A stockbroker has kept a daily record of the value of a particular stock over the years and finds that prices of the stock form a normal distribution with a mean of $8.52 with a standard deviation of $2.38. The stock price beyond which 0.05 of the distribution falls is .

$12.43

Step-by-step explanation:

Given :

Mean = $8.52

Standard deviation, = $2.38

Stock price which falls beyond 0.05 of the distribution is at the 95th percentile

The 95th percentile distribution has a Pvalue of 1.645 (standard normal table)

We obtain the value of x, with z = 1.645

Using the Zscore relation :

Zscore = (score - mean) / standard deviation

1.645 = (score - 8.52) / 2.38

Cross multiply :

1.645 * 2.38 = score - 8.52

3.9151 = score - 8.52

Score = 8.52 + 3.9151

Score = $12.4351

Stock price beyond 0.05 is $12.43

x = -3

y = -18

step-by-step explanation:

to solve by substitution, substitute one variable and solve for the other. then substitute again to find the remaining variable.

x-1/3(3x-9) = -3 since y=3x-9 substittute y.

x-1/3(3x-9)=-3

x + x +3 = -3

2x+3=-3

2x+3-3= -3-3

2x=-6

x=-3

substitute again into y=3x-9

y=3(-3)-9

y=-9-9

y=-18