Several years ago the proportion of Americans aged 18 - 24 who invested in the stock market was 0.20. A random sample of 25 Americans in this age group was recently taken. They were asked whether or not they invested in the stock market. The results follow:
At a .05 level of significance, use Excel to determine whether or not the proportion of Americans 18 - 24 years old that invest in the stock market has changed.

Question

Several years ago the proportion of Americans aged 18 - 24 who invested in the stock market was 0.20. A random sample of 25 Americans in this age group was recently taken. They were asked whether or not they invested in the stock market. The results follow:
  At a .05 level of significance, use Excel to determine whether or not the proportion of Americans 18 - 24 years old that invest in the stock market has changed.

Quizplus · Accepted Answer

The Answer of Several years ago the proportion of Americans aged 18 - 24 who invested in the stock market was 0.20. A random sample of 25 Americans in this age group was recently taken. They were asked whether or not they invested in the stock market. The results follow:
  At a .05 level of significance, use Excel to determine whether or not the proportion of Americans 18 - 24 years old that invest in the stock market has changed.

Several Years Ago the Proportion of Americans Aged 18 -