Answer:
P(X≥75)= 0.22663
Step-by-step explanation:
Hello!
The variable has a normal distribution with mean μ= 67 and a standard deviation δ= 8.
X~N(μ;δ²)
You need to find the probability that a randomly selected X value is at least 75, i.e. 75 or more, symbolically:
P(X≥75)
To calculate this probability is best to work using the standard normal distribution. This distribution is derived from the normal distribution. Considering a random variable X with normal distribution, mean μ and variance δ², the variable Z =(X-μ)/δ ~N(0;1) is determined.
The standard normal distribution is tabulated. Any value of any random variable X with normal distribution can be "converted" by subtracting the variable from its mean and dividing it by its standard deviation.
Using the formula and the values of the parameters of the population you have to standardize the value of X
Z= (X-μ)/δ = (75 - 67)/ 8= 0.75
Now you can express the probability under the standard normal distribution:
P(X≥75) = P(Z≥0.75)
The Z-tables show probability values P(Z≤z₁₋α)= 1 - α, then:
P(Z≥0.75)= 1 - P(Z<0.75)= 1 - 0.77337= 0.22663.
I hope it helps!
Answer:
56
Step-by-step explanation:
The answer is:
The answer is:
Step-by-step explanation:
Answer:
-7, 1
Step-by-step explanation:
The roots of an equation are the answers to the equation, where the graph of the equation intersects the x-axis. One can see that the points at which the graph intersect the x-axis are the following,
(-7, 0) and (1, 0), therefore the roots to the equation are the following;
-7, 1
Answer:
Speed = 25miles per hour
Step-by-step explanation:
Represent the time with x and the distance with y
So, from the attachment; we have the following details:
Required
Determine the constant speed
Because the train travelled at a constant speed, the speed can be calculated using:
Notice that the result of each division is the same.
Hence, the constant speed is:
Speed = 25miles per hour