Someone help me solve for X

Given the following sampling distribution of one mean with a sample size 49, from a normally distributed population, find the population standard deviation, o.79828588912497

In the following diagram it is given that dec, ab || dc, ad || eb, and ad is congruent to bc. a)why isn't abc a parallelogram even though it has a pair of parallel sides and a pair of congruent sides b)explain why be must be congruent to bc. further explain what type of triangle this makes triangle abc and what it tells you about angle 1 and angle 2c) finally why must angle 3 be congruent to angle 1? further, explain why we know that angle 3 is congruent to angle 2

Elizabeth is using a sample to study american alligators. she plots the lengths of their tails against their total lengths to find the relationship between the two attributes. which point is an outlier in this data set?