(a) To compute probabilities regarding the sample mean using the normal model, what size sample would be required? O A. The normal model cannot be used if the shape of the distribution is skewed right. OB. The sample size needs to be greater than or equal to 30. O C. Any sample size could be used. O D. The sample size needs to be less than or equal to 30. (b) What is the probability that a random sample of n =35 oil changes results in a sample mean time less than 15 minutes? The probability is approximately (Round to four decimal places as needed.) (c) Suppose the manager agrees to pay each employee a $50 bonus if they meet a certain goal. On a typical Saturday, the oil-change facility will perform 35 oil changes between 10 A.M. and 12 P.M. Treating this as a random sample, there would be a 10% chance of the mean oil-change time being at or below what value? This will be the goal established by the manager. There is a 10% chance of being at or belowa mean oil-change time of minutes. (Round to one decimal place as needed.)

what assumptions are required for a z-score hypthesis test?  A. all of the above B. The score in the sample are independant observations  C. the scores are obtained by random sampling  D. the distribution of sample means is normal

The distribution of income in some Third World countries is considered very right skewed (many very poor people, very few middle income people, and even fewer wealthy people). Suppose we pick a country with a severely right skewed distribution. Let the average salary be $2,000 per year with a standard deviation of $8,000. We randomly survey 1,000 residents of that country. a. What is the sampling distribution of the sample mean, including name of the distribution, its mean, error, and standard ?

a) Determine the standard deviation (s) of sunflower heights in the test plot which wasnot fertilized and the Pseudo-Standard deviation (PSD) of sunflower heights in the test plotwhich was fertilized. b) Consider the following three statements          A.If the median of X is greater than the mean of X than the distribution of X ispositively skewed.           B.For Normal populations the median and the mean are approximately equal.           C.The median and the Inter-quartile range are measures of variability in apopulation. c) Consider the following three statements          A.The correlation between two positive quantities is always positive.          B.If the correlation between X and Y is negative than the slope of        the regressionline for predicting Y from X is negative.          C.Pearsons correlation coefficient is always between -1 and +1. This is notnecessarily true for Spearmans correlation coefficient