Question

Trend lines

Help will be greatly appreciated!
The manager of fast food restaurant collected data to study the relationship between the number of employees working registers and the amount of time customers waited in line to order. He made a scatter plot of the data and credited a trend line with the equation y= -70x+300, where y is the total amount of time waited in seconds and x is the number of employees working registers.
1. Did the scatter plot of data positive, negative, or no association? Explain your reasoning.​
2. Maria went to the restaurant and waited 90 seconds to place her order. Use the trend line equation to predict how many employees were working.
3. Kiara went to the restaurant and waited 3.5 minutes. Use the trend line to predict how many employees are working.
4. Ashton walked into the restaurant and 4 employees are working registers. Use the trend line equation to predict how long he will wait to place his order.

Answer 1

Answer: the slope is 3 and the intercept is 0.

Step-by-step explanation:The trend line for the bivariate data shown in the scatter plot has the equation Y=3x

To determine the slope for a straight line (y=a*x+b)we take the two points that are shown and apply the following equation:

To determine the intercept we put the slope which we calculated into the equation for the point (2,6) and clear for b