Find the value of x 3,9,10,8,7,x the mean is 7

Ineeeeed this is due tomorrow and i dont know the answer can you find all the exponents

Which shows the correct substitution of the values a,b and c from the equation 1=-2x+3x^2+1

Ur environment is very sensitive to the amount of ozone in the upper atmosphere. the level of ozone normally found is 4.04.0 parts/million (ppm). a researcher believes that the current ozone level is not at a normal level. the mean of 2525 samples is 4.44.4 ppm with a standard deviation of 0.80.8. assume the population is normally distributed. a level of significance of 0.020.02 will be used. make the decision to reject or fail to reject the null hypothesis. answer tables