Question

for several years, graham has gathered data on students who own a computer and on their performance on a typing-speed test. he creates the linear model y = 3.8x + 17.4 where y represents the typing speed, in words per minute, of a student and x represents the number of years the student has owned a computer. according to graham’s model, what is the approximate speed of a student who has owned a computer for three years?
21 words/min
29 words/min
56 words/min
64 words/min

Explanation:

Step1: Identify the value of x

The student has owned a computer for 3 years, so \( x = 3 \).

Step2: Substitute x into the linear model

The linear model is \( y = 3.8x + 17.4 \). Substitute \( x = 3 \) into the equation:
\( y = 3.8\times3 + 17.4 \)

Step3: Calculate the value of y

First, calculate \( 3.8\times3 = 11.4 \). Then, add 17.4: \( 11.4 + 17.4 = 28.8 \approx 29 \).

Answer:

B. 29 words/min