Question

Keiko surveyed people with cell phones. Ages in years = a Texts they send per day = t He drew a best-fit line and determined its equation. Evaluate how many texts a 15 year old would send each day according to Keiko's trend line.

Answer 1

68 texts per day

Explanation:

The description of the variables in the equation tells you that you want to find t (texts sent per day) for the given value of 'a' (age in years).

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Substitute the number (15) for the variable (a) and do the arithmetic:

t = -1.63a +92.14

t = -1.63(15) +92.14 = -24.45 +92.14

t = 67.69

Keiko's trend line estimates a 15-year-old would send about 68 texts per day.