Answer:
The 95% confidence interval for the mean change in blood pressure, 
, is 1.744 < < 2.816
Step-by-step explanation:
The parameters given are;
The number of people in the sample, n = 9
The average drop in blood pressure, = 2.28 points
The standard deviation, σ = 0.82
The confidence level = 95%
The formula for confidence interval with a known mean is given as follows;
Where:
= z - score at 95% confidence level = 1.96
We therefore have;
Which gives the 95% confidence interval for the mean change in pressure, , is given as follows;
1.744 < < 2.816
Answer:
x = 4 and y = -3
Question;
Me pueden ayudar a resolver por método de sustitución porfa.
Translation: Can you help me to solve by please substitution method.
{5x+7y=-1
{-3x+4y=-24
Step-by-step explanation:
Given the simultaneous equation.
5x+7y=-1 .....1
-3x+4y=-24 .....2
From equation 2, making y the subject of formula.
4y = -24 + 3x
y = (-24+3x)/4 ...... 3
Substituting the equation 3 into equation 1
5x+7((-24+3x)/4) = -1
Multiply through by 4
20x + 7(-24+3x) = -4
20x - 168 + 21x = -4
41x -168 = -4
41x = -4 + 168
41x = 164
x = 164/41 = 4
x = 4
Substituting x = 4 into equation 3
y = (-24+3(4))/4
y = (-24+12)/4
y = -12/4
y = -3
