Answer:
And we can find this probability using the normal standard distribution or excel and we got:
Step-by-step explanation:
For this case we assume the following complete question: "The pucks used by the National Hockey League for ice hockey must weigh between 5.5 and 6 ounces. Suppose the weights of pucks produced at a factory are normally distributed with a mean of 5.86 ounces and a standard deviation of 0.13ounces. What percentage of the pucks produced at this factory cannot be used by the National Hockey League? Round your answer to two decimal places.
"
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 weights of a population, and for this case we know the distribution for X is given by:
Where
and
We are interested on this probability
And the best way to solve this problem is using the normal standard distribution and the z score given by:
If we apply this formula to our probability we got this:
And we can find this probability using the normal standard distribution or excel and we got:
Answer:
-43
Step-by-step explanation:
-2x2 + 2x - 3?
Let x = 5
-2 (5)^2 +2(5) -3
-2 (25) +10 -3
-50 +10 -3
-43
Answer:
0.0359
Step-by-step explanation:
Data provided:
mean values of three independent times are 15, 30, and 20 minutes
the standard deviations are 2, 1, and 1.6 minutes
Now,
New Mean = 15 + 30 + 25 = 65
Variance = ( standard deviation )²
or
Variance = 2² + 1² + 1.6² = 7.56
therefore,
Standard deviation = √variance
or
Standard deviation = 2.75
Thus,
Z-value = 
or
Z-value = - 1.81
from the Z-table
the Probability of Z ≤ -1.81 = 0.0359
Okay the first one is what u did lol
Answer:
The number of textbooks of each type were sold is <u>134 math </u>and <u>268 psychology </u>books.
Step-by-step explanation:
Given:
Total number of math and psychology textbooks sold in a week is 402.
Now, let the number of math textbooks sold be
.
And, the number of psychology textbooks be
.
According to question:


Dividing both sides by 3 we get:

So, total number of math textbooks were 134 .
And, total number of psychology textbooks were 
.
Therefore, the number of textbooks of each type were sold is 134 math and 268 psychology books.