A suitable probability calculator will tell you that probabilty is about 25.9%.
_____
The normalcdf function on this calculator gives an area between a lower and upper limit. If the upper limit is more than about 8 standard deviations above the mean, the 10th decimal place is unaffected. Since the standard deviation here is about 5, we need to have an upper limit that is about 40 above the mean of about 30. We have chosen 80 as a nice round number and to give a little more margin.
Answer:
a
f'(t) is negative
b
The unit is degC/min
c
At <u>35</u> minutes after the coffee was put on the counter, its temperature is <u>68</u> and will <u>decrease</u> by about <u>0.75</u> in the next 30 seconds.
Step-by-step explanation:
From the question we are told we are told that
The equation for the temperature of a cup of coffee place on a counter is
Here t is the time in minutes the coffee was put on the counter
Generally f(t)' is the derivative of f(t) at it represents the change of the temperature of the cup of coffee with respect to time
Generally for the coffee placed on the counter after a couple of minutes the temperature will decrease hence f(t)' is negative
Generally the unit of the temperature is in degrees Celsius while that of time is in minutes
So the change in temperature with time f(35)' will be in degrees Celsius/minutes (i.e degC/min)
From the question we are told that
i.e the rate of change of temperature after 35 minutes is 1.5
and
i.e the temperature of the cup of coffee after 35 minutes is 67 degC
Now after another t= 30 seconds = the rate of change of the temperature of the cup of coffee is
=>
=>
So
At <u>35</u> minutes after the coffee was put on the counter, its temperature is <u>68</u> and will <u>decrease</u> by about <u>0.75</u> in the next 30 seconds.
Answer:
2
Step-by-step explanation:
Given
See attachment for chart
Required
Number of off days
To do this, we simply calculate the expected value of the chart.
This is calculated as:
Where
x = days
f = chances
So, we have:
