Answer:
x = - 2
y = 6
Step-by-step explanation:
The best way to do this is to put - 3x in for y in the second equation.
4x - 2(-3x) = - 20 Watch the signs. You have 2 minus signs.
4x - - 6x = -20 Change - - 6x to 6x
4x + 6x = - 20 Add
10x = - 20 Divide by 10
x = -20/10
x = - 2
============================
Find y
y = - 3x
y = -3 * -2
y = 6
Answer:
12x-7y+3z
Step-by-step explanation:
Answer:
{13.7756,18.2244}
Step-by-step explanation:
Given the sample size, the margin of error can be calculated with the formula
where Z is the critical value for the desired confidence level, σ is the population standard deviation, and n is the sample size. Therefore, our margin of error for a 90% confidence level is:

The formula for a confidence interval is
where x-bar is the sample mean. Therefore, the 90% confidence interval for the mean amount of sushi pieces a person can eat is:
![CI=\bar{x}\pm[M]=16\pm2.2244={13.7756,18.2244}](https://tex.z-dn.net/?f=CI%3D%5Cbar%7Bx%7D%5Cpm%5BM%5D%3D16%5Cpm2.2244%3D%7B13.7756%2C18.2244%7D)
Therefore, we are 90% confident that the true mean amount of sushi pieces a person can eat is contained within the interval {13.7756,18.2244}

Hope that helps and hope you get better!
Answer:
0.0326 = 3.26% probability that a randomly selected thermometer reads between −2.23 and −1.69.
The sketch is drawn at the end.
Step-by-step explanation:
Normal Probability Distribution
Problems of normal distributions can be solved using the z-score formula.
In a set with mean
and standard deviation
, the z-score of a measure X is given by:

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the p-value, we get the probability that the value of the measure is greater than X.
Mean of 0°C and a standard deviation of 1.00°C.
This means that 
Find the probability that a randomly selected thermometer reads between −2.23 and −1.69
This is the p-value of Z when X = -1.69 subtracted by the p-value of Z when X = -2.23.
X = -1.69



has a p-value of 0.0455
X = -2.23



has a p-value of 0.0129
0.0455 - 0.0129 = 0.0326
0.0326 = 3.26% probability that a randomly selected thermometer reads between −2.23 and −1.69.
Sketch: