A sales manager for an advertising agency believes there is a relationship between the number of contacts and the amount of the sales. To verify this belief, the following data was collected: 
The 95% confidence interval for 30 calls is
Definitions:
Health Risks
Factors or conditions increasing the potential for developing a disease or incurring an injury.
Asthmatic Reactions
Physiological responses in asthmatics, such as wheezing or shortness of breath, triggered by various environmental factors.
Physiological Changes
Modifications in the body's functions or structures, often as a response to environmental, psychological, or internal stimuli.
Emotion Theories
Various theories that explain how and why people experience emotions, including biological, cognitive, and social perspectives.
Q14: A national manufacturer of ball bearings is
Q24: i. Social security, old-age pensions, many apartment
Q27: Multiple regression analysis is applied when analyzing
Q65: Listed below is the net sales in
Q67: To compare the effect of weather on
Q68: What must both np and n(1 -
Q70: What is variation within a year, such
Q74: i. One component of a time series
Q108: What do we call the statement that
Q113: For a two-tailed test at the 0.05