Question

00 Usman Haruna: Attempt 1 Use the following information for problems 9 16: Atrazine is a herbicide that selectively controls several species of weeds without harming crops. It is widely used on corn in the Gallatin Valley. If the atrazine concentration is too high, the herbicide has the potential to cause weight loss, cardiovascular damage, retinal and some muscle degeneration, and mammary tumors. Environmental Protection Agency (EPA) researchers measured atrazine concentrations (in mg/L) in both June and September at a random sample of 24 shallow groundwater sites in the Gallatin Valley. For each site, whether the atrazine concentration increased from June to September was recorded. Atrazine concentration increased from June to September in 15 of the 24 sites. 12 Question 9 (1 point) What is one observational unit? 15 EPA researcher Groundwater site Atrazine concentration Month 18 Ouestion 10 (1 point)

Answer 1

Ans-9)

a unit of observation is the unit described by the data that one analyzes. For example, in a study of the demand for money, the unit of observation might be chosen as the individual.

in this case Groundwater site is the unit of observation.

Ans-10)

Here variable of interest whether it atrazine is Quantitative Variable.

option(2) is true.

for more clarification you can see the definition of these variable which is given below.

Quantitative Variable- Variables that have are measured on a numeric or quantitative scale. while a categorical variable is a variable that can take on one of a limited, and usually fixed number of possible values, assigning each individual or other unit of observation to a particular group or nominal category on the basis of some qualitative property.

Ans-11)   the null hypothesis is a general statement or default position which be want to reject .in this case intial we assume there is no increase in atrazine concentration.

Ans(12)- OPTION(d) is correct.

type 2 error = P[ rejecting null hypothesis while alternative hypothesis is true]

since the EPA place stricter regulation on hirbecide regulation while antrazine is risen.

Ans(13) - False

Ans(14)-

When you perform a hypothesis test in statistics, a p-value helps you determine the significance of your results. ... The p-value is a number between 0 and 1 and interpreted in the following way: A small p-value (typically ≤ 0.10) indicates strong evidence against the null hypothesis, so you reject the null hypothesis.

here (0.1600> 0.10) hence there is weak evidence against the null hyp. hence we don't reject the null hypothesis.

Ans(15) option(c)-

No, because p value is larger than the significance level.

Ans(16)- Practically we want that null hypothesis should be rejected but here it will rejected since practically it is not important.

Ans(17)- both are right

null hyp. is hyp which we want to test.

Ans(19) option(c)

0.999