Step-by-step explanation:
In statistics, the empirical rule states that for a normally distributed random variable,
- 68.27% of the data lies within one standard deviation of the mean.
- 95.45% of the data lies within two standard deviations of the mean.
- 99.73% of the data lies within three standard deviations of the mean.
In mathematical notation, as shown in the figure below (for a standard normal distribution), the empirical rule is described as

where the symbol
(the uppercase greek alphabet phi) is the cumulative density function of the normal distribution,
is the mean and
is the standard deviation of the normal distribution defined as
.
According to the empirical rule stated above, the interval that contains the prices of 99.7% of college textbooks for a normal distribution
,

Therefore, the price of 99.7% of college textbooks falls inclusively between $77 and $149.
Answer:
I'm going to say C
it looks the most reasonable to me
Answer:
73
Step-by-step explanation:
Answer:
x=4.0625 cm
Step-by-step explanation:
The Pythagorean theorem states that the square of the hypotenuse of a right triangle equals the sum of the squares of the two legs.
Not knowing which is the hypotenuse, lets assume that (x+5)cm is the hypotenuse:
(x+5)^2= 9^2+(x-3)^2
(x^2+10x+25)=81+(x^2-6x+9)
x^2+10x+25=81+x^2-6x+9
16x=65
x=4.0625
Checking:
(4.0625+5)^2=9^2+(4.0625-3)^2
82.1289=82.1289
Matt simply divided the 8 students in the class by the amount of vinegar the teacher has (15). this is incorrect because in order to determine how many ounces each student should get you would divide the amount of vinegar by the amount of students, thus ending up with 15/8.