Answer:
The answer is x=57
Step-by-step explanation:
First, we would set the number to x.
Then, we turn the words into an equation.
x+75 = 3x-39
Isolate the x.
-2x = -114
So...
x = 57
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.
Answer:
The axis of symmetry is 
Step-by-step explanation:
we know that
In a vertical parabola, the axis of symmetry is equal to the x-coordinate of the vertex
In this problem we have a vertical parabola open upward
The x-coordinate of the vertex is equal to the midpoint between the zeros of the parabola
so

therefore
The axis of symmetry is 