X=2. You use substitution to put the y=3x-5 into 6x+3y=15.
So you get 6x+3(3x-5)=15
=6x+9x-15=15
add 15 on both sides to get the x's alone and add the x's together.
6+9=15 -- 15+15=30
15x=30
30/15 =2
x=2
Given that the<span> iq scores for large populations are centered at 100.
To get what percent of these 78 students have scores above 100 we conduct a normal distribution probability of the data.
P(x > 100) = P(z > (100 - 100)/sd) = P(z > 0) = 1 - P(z < 0) = 1 - 0.5 = 0.5 = 50%
</span>
Answer:
Step-by-step explanation:
We would set up the hypothesis test. This is a test of a single population mean since we are dealing with mean
For the null hypothesis,
µ = 17
For the alternative hypothesis,
µ < 17
This is a left tailed test.
Since the population standard deviation is not given, the distribution is a student's t.
Since n = 80,
Degrees of freedom, df = n - 1 = 80 - 1 = 79
t = (x - µ)/(s/√n)
Where
x = sample mean = 15.6
µ = population mean = 17
s = samples standard deviation = 4.5
t = (15.6 - 17)/(4.5/√80) = - 2.78
We would determine the p value using the t test calculator. It becomes
p = 0.0034
Since alpha, 0.05 > than the p value, 0.0043, then we would reject the null hypothesis.
The data supports the professor’s claim. The average number of hours per week spent studying for students at her college is less than 17 hours per week.
X = <span>weight of the baby.
y = </span>weight of the doctor.
z = weight of the nurse.
x + y = 78 so y = 78 - x
x + z = 69 so z = 69 - x
x + y + z = 142
substitute y = 78 - x and z = 69 - x into x + y + z = 142
x + y + z = 142
x +78 - x + 69 - x = 142
-x + 147 = 142
-x = - 5
x = 5
answer
<span>the weight of the baby was 5 kg</span>
The correct answer is Choice A.
If you plot the points on a graph, you will see that there is a slope of -1 and the y-intercept is (0, 3).
This matches the equation of y = -x + 3 in Choice A.
