Question

One method for measuring air pollution is to measure the concentration of ozone, or O3O3, in the air. Suppose Nina, an environmental scientist, wishes to estimate the O3O3 concentration in Lisbon, Portugal. She randomly selects 48 locations throughout the city measures the O3O3 concentration at each location. Based on her 48 samples, she computes the margin of error for a 95% ?t‑confidence interval for the mean concentration of O3O3 in Lisbon, in ?g/m3μg/m3, to be 2.68.

What would happen to the margin of error if

Nina decreases the confidence level to 90%?

Nina increases the confidence level to 99%?

Nina decreases the sample size to 34 locations?

Nina increases the sample size to 70 locations?

Answer Bank:

Increases

Stays the same

Decreases

Answer 1

Ans:

Nina decreases the confidence level to 90%?

Decreases,as lower the Confidence level,lower the margin of error.

Nina increases the confidence level to 99%?

Increases,as higher the Confidence level,higher the margin of error.

Nina decreases the sample size to 34 locations?

Increases,as smaller the sample size,larger the standard error,so larger the margin of error.

Nina increases the sample size to 70 locations

Decreases,as larger the sample size,smaller the standard error,so smaller the margin of error