Exponential functions in context (SAT) practice

The function $g$ is defined by $g(t) = 840(0.5)^{t/4}$. The function $g$ models the mass, in milligrams, of a medicine in a patient's bloodstream, where $t$ is the number of hours after an injection. According to the model, what is the estimated mass, in milligrams, of the medicine at the time of the injection?

The function $h$ is defined by $h(t) = 125(1.18)^t$. The function $h$ models the number of members in a club, where $t$ is the number of years after the club was founded. According to the model, what is the estimated number of members when the club was founded?

The function $N$ is defined by $N(t) = 680(0.72)^{t/8}$. The function $N$ models the number of particles detected in a radiation beam, where $t$ is the number of millimeters the beam has traveled into a shielding material. According to the model, what is the estimated number of particles in the beam at the surface of the shielding material?

The function $S$ is defined by $S(t) = 450(0.85)^{t/3}$. The function $S$ models the height, in centimeters, of a snowpack, where $t$ is the number of days after a winter storm. According to the model, what is the estimated height, in centimeters, of the snowpack $3$ days after the storm?

The function $I$ is defined by $I(t) = 275(1.04)^t$. The function $I$ models the balance, in thousands of dollars, of an investment account, where $t$ is the number of months after the account was opened. According to the model, what is the estimated balance, in thousands of dollars, of the account $1$ month after it was opened?

The function $L$ is defined by $L(w) = 180(0.88)^{w/2}$. The function $L$ models the light output, in lumens, from a bulb, where $w$ is the number of weeks the bulb has been in use. According to the model, what is the estimated light output, in lumens, after $2$ weeks of use?

The function $D$ is defined by $D(t) = 1{,}500(0.6)^{t/5}$. The function $D$ models the amount of a drug, in micrograms, in a patient's bloodstream, where $t$ is the number of hours after a dose is given. Which statement best describes what the factor $0.6$ represents in this model?

The function $R$ is defined by $R(t) = 900(0.5)^{t/12}$. The function $R$ models the intensity of background radiation, in millisieverts, measured $t$ months after a person enters an underground shelter. Which statement best describes what the $12$ in the expression $t/12$ represents?