A copy machine makes 133 copies in 4 minutes and 45seconds.how many copies does it make per minute ?
1 answer:
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Answer:
And using a calculator, excel ir the normal standard table we have that:
And we can calculate the probability like this:Step-by-step explanation:
A random sample of 36 observations has been drawn from a normal distribution with mean 50 and standard deviation 12. Find the probability that the sample mean is in the interval 47<=X<53. Is the assumption of normality important. Why?
Previous concepts
Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".
The Z-score is "a numerical measurement used in statistics of a value's relationship to the mean (average) of a group of values, measured in terms of standard deviations from the mean".
Solution to the problem
Let X the random variable that represent the variable of interest of a population, and for this case we know the distribution for X is given by:
Where and
Since the distribution for X is normal then we know that the distribution for the sample mean is given by:
We can find the probability required like this:
And using a calculator, excel ir the normal standard table we have that:
And we can calculate the probability like this:
Answer:
S(t) = a.sin (b.t) + d
a = -1.5, b = (2π/365), d = 3.47
S(t) = -1.5 sin (2πt/365) + 3.47
Step-by-step explanation:
Complete Question is presented in the attached image to this solution.
- Dingane has been observing a certain stock for the last few years and he sees that it can be modeled as a function S(t) of time t (in days) using a sinusoidal expression of the form
S(t) = a.sin(b.t) + d.
On day t = 0, the stock is at its average value of $3.47 per share, but 91.25 days later, its value is down to its minimum of $1.97.
Find S(t). t should be in radians.
S(t) =
Solution
S(t) = a.sin(b.t) + d.
At t = 0, S(t) = $3.47
S(0) = a.sin(b×0) + d = a.sin 0 + d = 3.47
Sin 0 = 0,
S(t=0) = d = 3.47.
At t = 91.25 days, S(t) = $1.97
But, it is given that T has to be in radians, for t to be in radians, the constant b has to convert t in days to radians.
Hence, b = (2π/365)
S(91.25) = 1.97 = a.sin(b×91.25) + d
d = 3.47 from the first expression
S(t = 91.25) = a.sin (91.25b) + 3.47 = 1.97
1.97 = a.sin (2π×91.25/365) + 3.47
1.97 = a sin (0.5π) + 3.47
Sin 0.5π = 1
1.97 = a + 3.47
a = -1.5
Hence,
S(t) = a.sin (b.t) + d
a = -1.5, b = (2π/365), d = 3.47
S(t) = -1.5 sin (2πt/365) + 3.47
Hope this Helps!!!
