Difference in Proportions and Means

A market researcher suspects that employees at Company A were older on average than employees at company B. They obtained a random sample of employees ages from each company. Results are shown. Which is the correct calculation for the t-statistic?

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A market researcher suspects that employees at Company A were older on average than employees at company B. They obtained a random sample of employees ages from each company. Results are shown. What is the p-value?

• 3.07

• 0.00163

• 57.7

• 0.0032

A market researcher suspects that employees at Company A were older on average than employees at company B. They obtained a random sample of employees ages from each company. Results are shown. What should the researcher conclude at the 5% significance level?

• There is strong evidence that employees at company A are older than those at company B.

• There is strong evidence that employees at company B are older than those at company A.

• There is no difference in the ages of employees at companies A & B.

• The independent assumption is violated; no conclusions can be made.

A market researcher suspects that employees at Company A were older on average than employees at company B. They obtained a random sample of employees ages from each company. Results are shown. Find a 95% confidence interval for the age differences between company A & company B.

• It appears employees at company A are 1.6 to 7.4 years older than company B.

• It appears employees at company B are 1.6 to 7.4 years older than company A

• It appears employees at company A are 2.0 to 7.0 years older than company B.

• It appears employees at company A are 2.0 to 7.0 years older than company B.

A health researcher was curious if women in India lived longer on average than men in India. They obtained data from a random sample of 216 records of people in India. Results are shown. What is the t-statistic?

• 0.0105

• -2.58

• 0.994

• 206.45

A health researcher was curious if women in India lived longer on average than men in India. They obtained data from a random sample of 216 records of people in India. Results are shown. What is the p-value?

• 0.00526

• -2.58

• 2.58

• 0.0152

A health researcher was curious if women in India lived longer on average than men in India. They obtained data from a random sample of 216 records of people in India. Results are shown. What should the researcher conclude?

• There is evidence at the 5% significance level that Indian women live longer than Indian men.

• There is evidence at the 5% significance level that Indian men live longer than Indian women.

• There is no evidence that Indian women live longer than Indian men.

• These populations cannot be independent; no conclusion can be drawn.

An economist wondered if average annual income between Norway and the US was different. He obtained incomes for a random sample of people from each country and converted the incomes into US dollars. The data is shown (in 1000's). What is the p-value?

• 0.0027

• 3.057

• 0.9986

• 0.0013

An economist wondered if average annual income between Norway and the US was different. He obtained incomes for a random sample of people from each country and converted the incomes into US dollars. The data is shown (in 1000's). What should the researcher conclude at a 5% significance level?

• There is a difference in annual incomes between the US and Norway.

• There is no difference in annual incomes between the US and Norway.

• No conclusion can be made; the random assumption is violated.

• Norway's annual income is lower than the US.

An economist wondered if average annual income between Norway and the US was different. He obtained incomes for a random sample of people from each country and converted the incomes into US dollars. The data is shown (in 1000's). Find a 90% C.I. for the difference in annual incomes between countries.

• There is a difference in annual incomes of between 5.0 and 16.8 thousand dollars more in Norway than the US.

• There is a difference in annual incomes of between 3.8 and 17.9 thousand dollars more in Norway than the US.

• No conclusion can be made; the random assumption is violated.

• Norway's annual income is lower than the US by several thousand US dollars.