In a survey conducted by a polling company, 1100 adult americans were asked how many hours they worked in the previous week. based on the results, a 95% confidence interval for the mean number of hours worked had a lower bound of 42.7 and an upper bound of 44.5. provide two recommendations for decreasing the margin of error of the interval. select all that apply. a. decrease the sample size.

b. use fewer degrees of freedom.

c. decrease the confidence level.

d. decrease the standard deviation of hours worked.

e. increase the confidence level. f. increase the sample size

Which of the following selections is least useful for supporting the claim that states intentionally built unequal school systems? question 1 options: the supreme court ruling in plessy v. ferguson (1896) wrote into law that america had two separate societies: one black and one white. it was very clear by the mid-1900s that southern states had expertly built separate educational systems. these schools, however, were never equal. states with laws keeping schools segregated never gave equal amounts of money to their black and white schools. ten years after brown, fewer than 10 percent of southern public schools had integrated. some areas did not comply at all.