Answer:
18
Step-by-step explanation:
There are 2+3 = 5 ratio units representing 45 band members, so each ratio unit represents 45/5 = 9 band members.
The 2 ratio units of sixth graders represent 2×9 = 18 sixth grade band members.
Answer:

Step-by-step explanation:
16 divided by 6 is 2.66666667
Since 1/3 is .33 , 2/3 is .66
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.