For the following reports about statistical studies, identify the following items (if possible). if you can't tell, then say so-this often happens when we read about a survey.
(i) the population: the soil around the former industrial waste dump
(ii) the parameter of interest: the mean level of toxic chemicals in the soil
(iii) the sample: the 20 soil samples
(iv) the sample statistic: the mean level of toxic chemicals in the 20 soil samples.
the environmental protection agency took soil samples at 16 locations near a former industrial waste dump and checked each for evidence of toxic chemicals. they found no elevated levels of any harmful substances.

Step-by-step explanation:

The above answer explanation can be more clear by understanding that the population is the soil around the former waste dump and the samples are 16   which were taken from  EPA.In report, the method is unclear too.

∠1≅∠2 by the alternate exterior angles theorem.

step-by-step explanation:

given, a ∥ b and ∠1 ≅ ∠3 .we have to prove that e ∥ f

we know that ∠1≅∠3 and that a || b because they are given. we see that by the alternate exterior angles theorem. therefore, ∠2≅∠3 by the transitive property. so, we can conclude that e || f by the converse alternate exterior angles theorem.

we have to fill the missing statement.

transitivity property states that if a = b and b = c, then a = c.

now, given ∠1≅∠3 and by transitivity property ∠2≅∠3 .

hence, to apply transitivity property one angle must be common which is not in result after applying this property which is ∠1.

the only options in which ∠1 is present are ∠1 and ∠2, ∠1 and ∠4

∠1 and ∠4 is not possible ∵ after applying transitivity we didn't get ∠4.

hence, the missing statement is ∠1≅∠2.

so, ∠1≅∠2 by the alternate exterior angles theorem.