Question

15.7 check your understanding
the scatter plot represents data collected about the number of symptomatic cases of influenza, also called the flu, in millions, in the u.s. since 2011.
the equation y = 2.34x + 19.1 can be used to model the relationship, where y is the number of symptomatic cases of the flu in the u.s., in millions, and x is the number of years since 2011. use the model to complete the statement.
the y - intercept of the model is and can be interpreted as

Explanation:

Step1: Recall y - intercept formula

For a linear equation in the form $y = mx + b$, the y - intercept is $b$.
The given equation is $y = 2.34x+19.1$.

Step2: Identify the y - intercept

By comparing with $y = mx + b$, we can see that $b = 19.1$.
The interpretation of the y - intercept in the context of the problem is that in the year 2011 (when $x = 0$ years since 2011), the number of symptomatic cases of the flu in the U.S. was 19.1 million.

Answer:

19.1; In 2011, the number of symptomatic cases of the flu in the U.S. was 19.1 million.