you intend to estimate a popolulation mean with a confidence interval. you believe the population to have a normal distribution . your sample size is 4. find the critical value that corresponds to a confidence level of 91 %​

question 1: step-by-step explanation:

1/4 of 84 = 84÷4= 21

  or  

sin y = 7/q

7 is the opposite side length, q is the hypotenuse

tan y = 7/r

7 is the opposite side length, r is the adjacent side length

using sohcahtoa ^^^^

cos y = adjacent/hypotenuse

cos y = r/q