Consider a study conducted in 2018, where researchers wanted to estimate the percentage of middle school girls who planned to major in a STEM field. Complete parts (a) and (b) below. a. If a 95%...

Extracted text: Consider a study conducted in 2018, where researchers wanted to estimate the percentage of middle school girls who planned to major in a STEM field. Complete parts (a) and (b) below. a. If a 95% confidence level is used, how many people should be included in the survey if the researchers wanted to have a margin of error of 3%? There should be people included in the survey. (Round to the nearest person as needed.) b. How could the researchers adjust their margin of error if they want to decrease the number of study participants? O A. No changes to the margin of error will affect the number of study participants needed. B. They could either increase or decrease the margin of error. C. They could decrease their margin of error. D. They could increase their margin of error.