Arandom sample of 25 fields of rye has a mean yield of 31.2 bushels per acre and standard deviation of 6.99 bushels per acre. determine the 80% confidence interval for the true mean yield. assume the population is approximately normal. step 1 of 2: find the critical value that should be used in constructing the confidence interval. round your answer to three decimal places.

Critical value is 1.318 and the confidence interval is 29.357 to  33.042

Step-by-step explanation:

n = 25

x = 31.2

s = 6.99

Degree of freedom = n-1= 25-1 =24

Confidence level = 0.8

So, α = 1- 0.8= 0.2

t critical =

Formula of confidence interval : to  

Confidence interval : to  

Confidence interval : to  

Hence critical value is 1.318 and the confidence interval is 29.357 to  33.042

the equation cos(35) =a/25 can be used to find the length of bc what is the length of bc? round to the nearest tenth

step-by-step explanation:

18

step-by-step explanation:

draw the shape and you will see that f and k are actually at adjacent vertices (points of the hexagon that are neighboring).   so find the distance between (1,2) and (4,2).   that is easy since (1,2) and (4,2) is just a vertical distance to count, which is 3.   it is a regular polygon which means all sides are congruent.   you have 6 sides (hexa) so multiply 6 by 3 to receive 18.