Answer:
The maximum speed of Hal's airplane in still air is:

The speed of the wind

Step-by-step explanation:
Remember that the velocity v equals the distance d between time t.
and 
The distance that Hal travels when traveling with the wind is:
miles
Where v is the speed of Hal and c is the wind speed.
The distance when traveling against the wind is:
miles
Now we solve the first equation for v




Now we substitute the value of v in the second equation and solve for c







Then:


The maximum speed of Hal's airplane in still air is:

The speed of the wind

Answer:
See below.
Step-by-step explanation:
m∠A + m∠B = m∠B + m∠C
Use the subtraction property of equality to subtract m<B from both sides of the equation.
m∠A + m∠B - m<B = m∠B - m<B + m∠C
m∠A = m∠C
Contradictions usually mean they go against established rules. Squaring a negative number is one example if it is in math. But just think of anything that goes against what is known.
Answer:
The standard deviation of the data set is
.
Step-by-step explanation:
The Standard Deviation is a measure of how spread out numbers are. Its symbol is σ (the greek letter sigma)
To find the standard deviation of the following data set

we use the following formula

Step 1: Find the mean
.
The mean of a data set is the sum of the terms divided by the total number of terms. Using math notation we have:


Step 2: Create the below table.
Step 3: Find the sum of numbers in the last column to get.

Step 4: Calculate σ using the above formula.
