Answer:


Step-by-step explanation:
Previous concepts
Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".
The Z-score is "a numerical measurement used in statistics of a value's relationship to the mean (average) of a group of values, measured in terms of standard deviations from the mean".
Solution to the problem
Let X the random variable that represent the grade points avergae of a population, and for this case we know the following properties
Where
and
The empirical rule, also referred to as the three-sigma rule or 68-95-99.7 rule, is a statistical rule which states that for a normal distribution, almost all data falls within three standard deviations (denoted by σ) of the mean (denoted by µ). Broken down, the empirical rule shows that 68% falls within the first standard deviation (µ ± σ), 95% within the first two standard deviations (µ ± 2σ), and 99.7% within the first three standard deviations (µ ± 3σ).
So we can find the z score for the value of X=3.44 in order to see how many deviations above or belowe we are from the mean like this:

So the value of 3.44 is 2 deviations above from the mean, so then we know that the percentage between two deviations from the mean is 95% and on each tail we need to have (100-95)/2 = 2.5% , because the distribution is symmetrical, so based on this we can conclude that:

Answer:
B. 5 rolls
Step-by-step explanation:
The areas of the room, not including the ceiling, are discriminated as follows:
Longer walls:
(6 inches equals one foot)
Shorter walls:
(6 inches equals one foot)
Window area: 
Door area: 
Area that will be effectively covered:
Total area to wallpaper: 
Amount of paper needed: 
That is, the area of a roll of paper is 
Number of rolls needed:
rolls
Converting a decimal to a mixed number is very simple when you get the hang of it. Since 8 is before the decimal, that is your number in the mixed number. For the fraction part, it's 77/100. The denominator is 100 because when you count the decimal places, it goes to hundredths. 77/100 is already in simplest form, so your final answer is 8 77/100.