Question

It is believed that 11% of all Americans are left-handed. A college needs to know how many left-handed desks to place in the big lecture halls being constructed on its campus. In a random sample of 290 students from that college, whether or not a student was left-handed was recorded for each student. The college wants to know if the data provide enough evidence to show that students at this college have a different percentage of left-handers than the general American population? State the random variable, population parameter, and hypotheses. State the Type I and Type II errors in the context of this problem.

Answer 1

Step-by-step explanation:

• The random variable (x) here would be a randomly selected student from the college that is left-handed.

• The population parameter would be 11% of America's total population. The total population as of 2019 is believed to be 328.2 million, and 11% of that figure is about 36.1 million (thirty-six million one hundred thousand).
• Hypotheses: Remember, the null hypothesis usually reflects the held view of the researcher, and since we are told the college wants to know if the data provide enough evidence to show that students at this college have a different percentage of left-handers than the general American population. It could read; There is a statistically significant difference in the percentage of left-handers in the college than the American population. While the alternate hypothesis could read; There is no statistically significant difference in the percentage of left-handers in the college than the American population.

• The Type I error implies rejecting the null hypothesis when it is actually true. That is: Rejecting that the % of all students from that college that are left-handed is 11 % when the % is really 11 %.

• The Type II error implies accepting the null hypothesis when it is actually false. That is: Failing to reject that the % of all students from that college that are left-handed is 11 % when the % is actually different.