Suppose that your quiz grade has a z-score of 1.5. How many standard deviation away from the mean is your quiz grade? 0 1.5 standar deviations above the mean O Unknown. Not enough information is given O No answer text provided. 0 1.5 standard deviations below the mean For the standard normal distribution, find the given probability: P( -2 1.23) *round your answer to the three digits. 0.109What are the properties of the standard normal random variable? (select all that apply) C] The probability density curve is a straight line C] The z-score can not be negative It's symmetric about the mean The total area under the probability density curve is 1