Complete question :
Mr. Nelson lost one of his students' test papers. He knows that the other 4 students scored as follows: 60, 62, 56, 57. He also knows that the average score is 59.2. What is the score on the missing paper?
Answer:
61
Step-by-step explanation:
Given the following :
Total number of students = 4 + 1 missing = 5
Score on the four avaliable papers = 60, 62, 56, 57
Average score of the 5 papers = 59.2
Score on missing paper :
Sum of each score / number of papers
Sum of each score = sum of available scores + missing score
Let missing score = m
(60 + 62 + 56 + 57 + m) = 235 + m
Recall:
Average = total sum / number of observations
Hence,
59.2 = (235 + m) / 5
59.2 × 5 = 235 + m
296 = 235 + m
m = 296 - 235
m = 61
Missing score = 61
Answer:
0.36427
Step-by-step explanation:
Mean = λ = 18 messages per hour
P(X = x) = (e^-λ)(λ⁻ˣ)/x!
P(X ≤ x) = Σ (e^-λ)(λ⁻ˣ)/x! (Summation From 0 to x)
But the probability required is that the messages thay come in an hour is between 15 and 20, that is, P(15 < X < 20)
P(15 < X < 20) = P(X < 20) - P(X ≤ 15)
These probabilities will be evaluated using a cumulative frequency calculator.
P(X < 20) = 0.65092
P(X ≤ 15) = poissoncdf(18, 15) = 0.28665
P(15 < X < 20) = P(X < 20) - P(X ≤ 15) = 0.65092 - 0.28665 = 0.36427.
You can use the Poisson distribution calculator here
https://stattrek.com/online-calculator/poisson.aspx
Answer:
Step-by-step explanation:
The populational growth is exponential with a factor of 1.12 each year. An exponential function has the following general equation:
Where 'a' is the initial population (25,000 people), 'b' is the growth factor (1.12 per year), 'x' is the time elapsed, in years, and 'y(x)' is the population after 'x' years.
Therefore, the function P(t) that models the population in Madison t years from now is:
The equation: n - 4 = -15
Now let's solve our equation for n.
n - 4 = -15
Add 4 to both sides.
n = -11
The maximum speed of a boat at 30 feet length of water is 0.093 nautical miles/hour or knots.
<u>Step-by-step explanation:</u>
- The equation for the maximum speed, s is given by s²= (16/9)x
- where, x is the length of the water line in feet.
It is given that, the modeled equation s²= (16/9)x is used to find the maximum speed in knots or nautical miles per hour.
The question is asked to find the maximum speed when the length of the water is 30 feet.
Therefore, to find the maximum speed in 30 feet water, the given modeled equation is used. So, substitute the 30 feet in place of x.
<u>Now, calculating the maximum speed :</u>
s² = (16/9)(30)
s² = 480 / 9
s² = 53.3
Taking square root on both sides,
s = √53.3
s = 7.3
The maximum speed of a boat at 30 feet length of water is 7.3 nautical miles/hour or knots.
