Solve for a, x, and y. pls help

Describe in detail how you would construct a 95% confidence interval for a set of 30 data points whose mean is 20 and population standard deviation is 3. be sure to show that you know the formula and how to plug into it. also, clearly state the margin of error.

On new year's day, the average temperature of a city is 5.7 degrees celsius. but for new year's day 2012, the temperature was 9.8 degrees below the average. i) if a represents the average temperature on new year's day and 7 represents the temperature on new year's day 2012, what formula accurately relates the two values together? ii) what was the temperature on new year's day 2012? dt a 0.8 ii) - 4 1 degrees celsius da-t-98 ii) 59 degrees celsius 1) 7 = -9,8 11) 59 degrees celsius ii) l degrees celsius

Askateboard ramp is in the shape of a right triangle what is the height of the ramp