Answer:
we have 2 real solutions
Step-by-step explanation:
ax^2 + bx+c
discriminant
b^2-4ac
6x=-2x^2-3
subtract 6x from each side
0 = -2x^2 -6x-3
a= -2
b=-6
c=-3
b^2-4ac = (-6)^2 - 4(-2) (-3)
36 - 24
12
if > 0 2 real solutions
= 0 1 real solution
< 0 2 complex solution
since 12 > 0 we have 2 real solutions
The question is incomplete! Complete question along with answer and step by step explanation is provided below.
Question:
How large of a sample of state employees should be taken if we want to estimate with 98% confidence the mean salary to be within $2,000? The population standard deviation is assumed to be $10,500. z-value for 98% confidence level is 2.326.
Answer:
Sample size = n = 150
Step-by-step explanation:
Recall that the margin of error is given by
Re-arranging for the sample size (n)
Where z is the value of z-score corresponding to the 98% confidence level.
Since we want mean salary to be within $2,000, therefore, the margin of error is 2,000.
The z-score for a 98% confidence level is 2.326
So the required sample size is
Therefore, we need to take a sample size of at least 150 state employees to estimate with 98% confidence the mean salary to be within $2,000.
Answer:
third one
1/6 y+1/6 (y+12)-2 is equivalent to 1/3 y.