Problem 1.) A researcher claims that 96% of college graduates say their college degree has
been a good investment. In a random sample of 2000 graduates, 1500 say their college degree has
been a good investment. At a = 0.05 is there enough evidence to reject the researcher's claim?

 |Z| = |-52.5|  = 52.5 > 1.96 at 0.05 level of significance

 Null  hypothesis is rejected

We rejected the researcher's claim

A researcher do not claims that 96% of college graduates say their college degree has been  a good investment.

Step-by-step explanation:

Explanation:-

Given data A researcher claims that 96% of college graduates say their college degree has  been a good investment.

Population proportion 'P' = 0.96

                                       Q = 1-P = 1- 0.96 = 0.04

In a random sample of 2000 graduates, 1500 say their college degree has

been a good investment.

Sample proportion

Level of significance  ∝ = 0.05

Test statistic

    |Z| = |-52.5|  = 52.5 > 1.96 at 0.05 level of significance

  Null  hypothesis is rejected

  We rejected the researcher's claim

Conclusion:-

A researcher do not claims that 96% of college graduates say their college degree has been  a good investment.

a.   since the profit made in 2012 is equal to the profit made in 2014, the profit is symmetric about the line y = 120,000.

step-by-step explanation: