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 scores of a population, and for this case we know the distribution for X is given by:
Where 
and 
We are interested on this probability
And the best way to solve this problem is using the normal standard distribution and the z score given by:
If we apply this formula to our probability we got this:
And we can find this probability using the normal standard table or excel and we got:
Answer:
The margin of error of the 90% confidence interval of a student's average typing speed is of 1.933 wpm.
Step-by-step explanation:
We have the standard deviation for the sample, which means that the t-distribution is used to solve this question.
The first step to solve this problem is finding how many degrees of freedom, we have. This is the sample size subtracted by 1. So
df = 20 - 1 = 19
90% confidence interval
Now, we have to find a value of T, which is found looking at the t table, with 19 degrees of freedom(y-axis) and a confidence level of 
. So we have T = 1.7291
The margin of error is:
In which s is the standard deviation of the sample and n is the size of the sample. For this question, we have 
. So
The margin of error of the 90% confidence interval of a student's average typing speed is of 1.933 wpm.
Initial value is the value of y where x = 0 (y-intercept).
You are already given that line contains point (0, 5). The y-coordinate is 5 therefore answer is C.
Please mark Brainliest
If you mean how do you get x by it's you divide both sides by 8, to cancel out the multiplication between x and 8, meaning that it would end up being x=7, sorry if that didn't answer your question correctly.
To find the cost per pound of rice, we can divide.
10 / 24 ≈ $0.42
A pound of rice approximately costs $0.42
Best of Luck!
