We have been given for a normal distribution the mean time it takes to walk to the bus stop is 8 minutes with a standard deviation of 2 minutes. And the mean time it takes for the bus to get to school is 20 minutes with a standard deviation of 4 minutes.
(a) Average time that it would take reach school can be obtained by adding the average times.
8+20 = 28 minutes.
(b) Standard deviation of the trip to school can be found as:
Therefore, standard deviation of the entire trip is 4.47 minutes.
(c) Let us first find z score corresponding to 30 minutes.
We need to find the probability such that
Therefore, the required probability is 0.67.
(d) If average time to walk to school is 10 minutes, then overall average time for the trip will be 10+20 = 30 minutes.
(e) Standard deviation won't change it will remain 4.47
(f) The new probability will be:
Therefore, probability will be 0.50.
Answer:
B) Rational
Step-by-step explanation:
The square root of .0081 is .09, which is a very real number
Answer:
True
Step-by-step explanation:
Hi, the statement is true, because to divide a fraction we have to turn the second fraction upside down and multiply them. Since a whole number x can be written as x/1, it also applies to the case of dividing a fraction by a whole number.
We can prove it with an example.
Dividing a unit fraction by a whole number
1/2 ÷ 2 = (1x1) / (2x2) = 1/4
Multiplying the unit fractions by a unit fraction with a whole number as a denominator
1/2 x 1/2= (1x1) / (2x2) = 1/4
In the early months of some year one site added 0.4 million new accounts every day, At this rate , how many days would be needed to add 24 million new accounts?
Answer:
A.
Step-by-step explanation:
The Elimination Method is the method for solving a pair of linear equations which reduces one equation to one that has only a single variable.
If the coefficients of one variable are opposites, you add the equations to eliminate a variable, and then solve.
If the coefficients are not opposites, then we multiply one or both equations by a number to create opposite coefficients, and then add the equations to eliminate a variable and solve.
When multiplying the equation by a coefficient, we multiply both sides of the equation (multiplying both sides of the equation by some nonzero number does not change the solution).
So, option B is not allowed (it is not allowed to multiply only one part of the equation)