"For a recent history test, scores follow the normal distribution with a mean of 70 points. 80% of the students scoblack below 88 points. What is the standard deviation of the scores? I have done a lot of research into the question and eventually broke down and used the standard table. The answer I got through that was a std of 21.387. I know I need to use the z score formula (x-mean)/std = z but I am searching for two of those variables and would need the z score at least to find the std. A push in the right direction would be greatly appreciated."

What is the range of the function ${\displaystyle y=x^2}$?

The domain and range of $y=\sin <!--\; \; -->x$ is
A)$R,[0,\mathrm{\infty <!--\; \infty \; -->}]$
B)$R,[-<!--\; -\; -->1,1]$
C)$R,[-<!--\; -\; -->\mathrm{\infty <!--\; \infty \; -->},\mathrm{\infty <!--\; \infty \; -->}]$
D)$R,[1,\mathrm{\infty <!--\; \infty \; -->}]$

Mean of the squares of the deviations from mean is called the:
Variance
Standard deviation
Quartile deviation
Mode

How to evaluate P(10,2)?

What is the effect of wind speed on evaporation?

What is the range of a linear function?

Find the range of ${\displaystyle \frac{x^2}{1-x^2}}$

State the main limitations of statistics.

What is the range of the function y = x?

Tell whether the statement is true or false : A data always has a mode.

In most cases,_____variables are not considered to be equal unless they are exactly the same.

A local newspaper in a large city wants to assess support for the construction of a highway bypass around the central business district to reduce downtown traffic. They survey a random sample of 1152 residents and find that 543 of them support the bypass. Construct and interpret a 95% confidence interval to estimate the proportion of residents who support construction of the bypass.

$3+3x3-3+3=?$What is the right answer and how?

Define lateral displacement.