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3 years ago

PLEASE HELP ASAP!!! CORRECT ANSWER ONLY PLEASE!!! I CANNOT RETAKE THIS!!

Mathematics

1 answer:

kipiarov [429]3 years ago

6 0

$T(t) = T_s + (T_0 - T_s)e^{-kt}$

$T(t) - T_s = (T_0 - T_s)e^{-kt}$

$\dfrac{ T(t) - T_s}{T_0 - T_s} = e^{-kt}$

$\ln \dfrac{ T(t) - T_s}{T_0 - T_s} = -kt$

$k = - \dfrac{ \ln \dfrac{ T(t) - T_s}{T_0 - T_s} }{t}$

OK now let's plug in the numbers.

We have t=15 minutes, T_0 = 80 C, Ts = 50, T(15)=60 C,

$k = - \dfrac{ \ln \dfrac{ 60 - 50}{80 - 50} }{15 \textrm{ min}}$

$k = - \frac{1}{15} \ln \frac 1 3$

$k = \frac{1}{15} \ln 3$

$k \approx 0.07324$ per minute

Answer: B

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Step-by-step explanation:

Problems of normally distributed samples are solved using the z-score formula.

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The first step to solve the question is find the probability that a student has of scoring above 1520, which is 1 subtracted by the pvalue of Z when X = 1520.

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Each students has a 0.4721 probability of scoring above 1520. So

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Answer:

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x = -1

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Put the 'x' and 'y' coordinates together in an ordered pair, which you write as (x, y).

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