Answer:
It is an unusual result contradicting the national survey.
Step-by-step explanation:
National survey showed 44% of college students who drink.
The professor's survey showed that 96/244 = 39% drink.
The professor's survey deviated from the national survey is 5% (44% - 39%) representing about 0.25% (5% squared) variance.
Standard deviation is the spread of a set of numbers from their mean. In other words, it measures how far an observed value is from the mean. It can be calculated by getting the square root of the variance.
The given expression for the area, 81x² - 4y², is a difference of two squares. The first term is the square of 9x and the second term is the square of 2y. The factors of this difference and the therefore the dimensions of the rectangle are, 9x - 2y and 9x + 2y.
Answer: B. 150
48-5=43
43+7=50
50•3=150