Answer:
628
Step-by-step explanation:
We have the standard deviation of the sample, so we use the t-distribution to solve this question.
The first step to solve this problem is finding how many degrees of freedom, we have. This is the sample size subtracted by 1. So
df = 12 - 1 = 11
95% confidence interval
Now, we have to find a value of T, which is found looking at the t table, with 11 degrees of freedom(y-axis) and a confidence level of 
. So we have T = 2.2
The margin of error is:
In which s is the standard deviation of the sample and n is the size of the sample.
The lower end of the interval is the sample mean subtracted by M. So it is 665 - 37 = 628 hours.
The answer is 628
Step-by-step explanation:
In mathematics, an algebraic expression is an expression built up from integer constants, variables, and the algebraic operations. For example, 3x² − 2xy + c is an algebraic expression. Since taking the square root is the same as raising to the power, is also an algebraic expression.
Answer:
The parabola's axis of symmetry is x = -6
Step-by-step explanation:
Parabola general equation:
y = a*(x - r1)*(x - r2)
Equation given:
y = (-1/4)*(x + 2)*(x + 10)
a = -1/4
r1 = -2
r2 = -10
To check if the parabola passes through the point (2, 10) it is necessary to replace x = 2 and check the y-value, as follows:
y = (-1/4)*(2+ 2)*(2 + 10) = -12
Then, point (2, 10) is not included in the parabola.
If a > 0 then the parabola opens upward; if a < 0 then the parabola opens downward. Then, the parabola opens downward
Axis of symmetry:
h = (r1 + r2)/2
h = (-2 + -10)/2 = -6
Then, The parabola's axis of symmetry is x = -6
To find Parabola's vertex, replace with the axis of symmetry:
y = (-1/4)*(-6 + 2)*(-6 + 10) = 4
Therefore, the parabola has a vertex at (-6, 4)
Answer: 45 mph
Step-by-step explanation:
We know that Rob was driving 63 mph which is 18 miles faster than pigeons, therefore you subtract to get the answer.
63-18=45
