find critical z subscript alpha/2 corresponds give degree confidence 86%

in a random sample of 500 u.s. airways flights departing phoenix sky harbor airport in january 2008, 401 departed on time. a similar sample of southwest airlines flights showed 359 departing on time. at the .01 significance, is there evidence that the proportion of u.s. airways flights departing...

Find the area under the standard normal curve for the following: P(z<-0.37), P(-1.88<z<0), P(-1.12<z<0.48)

Final averages are typically approximately normally distributed with a mean of 70 and a standard deviation of 10.5. Your professor says that the top 9% of the class will receive an A; the next 20%, a B; the next 40%, a C; the next 21%, a D; and the bottom 10%, an F. (Give your answers correct to...

how do you prove that estimators are unbiased?

These questions require the use of SPSS for statistics. Can you please help me answer them? I would really appreciate it! Thanks! Stephanie

Dr. Zak also gave his students the Beck Depression Inventory (BDI). The correlation between his test and the BDI was r =.14. Evaluate this correlation. What does this correlation tell us about the relationship between these two instruments?

a company manufactures batteries of 13 and there is a 3% rate of defects. Find the standard deviation for the number of defects per batch

means of 30 pounds and standard deviation 1.6 pounds. what is the probablility that the mean of 5 specimens exceeds 50 pounds?

A simple random sample of pulse rates of 40 women results in a standard deviation of 12.5 beats per minutes. The normal range of pulse rates of adults is typically given as 60 to 100 beats per minutes. If the range rule of thumb is applied to that normal range, the result is a standard deviation...