Answer:
12
Step-by-step explanation:
Hi!
To compare this two sets of data, you need to use a t-student test:
You have the following data:
-Monday n1=16; <span>x̄1=59,4 mph; s1=3,7 mph
-Wednesday n2=20; </span>x̄2=56,3 mph; s2=4,4 mph
You need to calculate the statistical t, and compare it with the value from tables. If the value you obtained is bigger than the tabulated one, there is a statistically significant difference between the two samples.

To calculate the degrees of freedom you need to use the following equation:

≈34
The tabulated value at 0,05 level (using two-tails, as the distribution is normal) is 2,03. https://www.danielsoper.com/statcalc/calculator.aspx?id=10
So, as the calculated value is higher than the critical tabulated one,
we can conclude that the average speed for all vehicles was higher on Monday than on Wednesday.
#1)
Answer:
x=1 and y=12
Explanation:
y=5x+7
y=2x+10
This system should use substitution because the value of y is given in terms if x.
Substitution:
5x+7=2x+10
Solve:
3x=3
x=1
Substitute x to solve for y by plugging x into one if the original equations(doesn’t matter which one is used).
y=5x+7
y=5(1)+7
y=5+7
y=12
#2)
Answer:
x=-8 and y=2
Explanation:
y=2x+18
9y=-2x+2
This system also uses substitution. The value of y us already given in terms if c in the first equations, so we will substitute in the second equation.
Substitute:
9(2x+18)=-2x+2
Solve:
18x+162=-2x+2
20x=-160
x=-8
Now that we have the value if x, plug it into one of the original equations(doesn’t matter which equation) and substitute to find y.
y=2x+18
Substitute:
y=2(-8)+18
Solve:
y=-16+18
y=2