At the size of obtuse angle DOF, giving a reason for your answer. +
2x52=104
DOF=104
the angle at the centre is twice the angle on the circle,
subtended on the same arc so DF =104°
F

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