Solve the following system of equations for all three variables. 7x + 9y – 2z = 9

X – 9y – z = -3

- 8x – 9y + 5z = 6

1. why is a frequency distribution useful? it allows researchers to see the "shape" of the data. it tells researchers how often the mean occurs in a set of data. it can visually identify the mean. it ignores outliers. 2. the is defined by its mean and standard deviation alone. normal distribution frequency distribution median distribution marginal distribution 3. approximately % of the data in a given sample falls within three standard deviations of the mean if it is normally distributed. 95 68 34 99 4. a data set is said to be if the mean of the data is greater than the median of the data. normally distributed frequency distributed right-skewed left-skewed

The angle of elevation from point a to the top of the cliff is 38 degrees. if point a is 80 feet from the base of the cliff , how high is the cliff ?

Right ∆abc has coordinates a(-7, 3), b( -7, 10), and c(-1, 3). the triangle is reflected over the x - axis and then reflected again over the y - axis to create ∆a'b'c'. which are the coordinates of vertex a'?