Let his total money be x.
He spent (3/7)*x of his money.
He gave 1/4(x-3/7x) to his sister.
which is : (1/4)*(4/7)*x = (1/7)*x
Now,
How much money he have in the beginning =
(3/7)*x+(1/7)*x+120=x
(4/7)*x+120=x
120=x-(4/7)*x
120=(3/7)*x
x=120*7/3 [cross multiplication]
x=280.
So, Alex had $280 in the beginning.
Answer:
What language is this so I can transalate and answer. If this even us a language
Step-by-step explanation:
Answer:
For this case the value of r = -0.66
Now we can calculate the determination coeffcient:

And then we can conclude that 43.56% of the variation in y can be explained by the explanatory variable
And then 100-43.56 = 56.44 % of the variation in y that cannot be explained by the explanatory variable
Step-by-step explanation:
For this case we need to calculate the slope with the following formula:
Where:
And we can find the intercept using this:
And the model obtained for this case is:

The correlation coefficient is a "statistical measure that calculates the strength of the relationship between the relative movements of two variables". It's denoted by r and its always between -1 and 1.
And in order to calculate the correlation coefficient we can use this formula:
For this case the value of r = -0.66
Now we can calculate the determination coeffcient:

And then we can conclude that 43.56% of the variation in y can be explained by the explanatory variable
And then 100-43.56 = 56.44 % of the variation in y that cannot be explained by the explanatory variable
Answer:
Step-by-step explanation:
A matched pair t test is one in which the set of data is divided into two sets of data and the test is done to test the difference between the pairs. Sometimes this is called paired t test.\
This is done normally where one group of sample or population can be paired with other group of sample /population.
Hence
A .Measurements of annual income for each twin for 100 randomly selected pairs of twins -- True
B. Measurements of annual income for both individuals in pairs formed by matching 100 people from State A and 100 people from State B based on level of education -- True
C. Measurements of annual income for both individuals in pairs formed by assigning 100 people to pairs at random -- True
D. Measurements of annual income recorded for both spouses of 100 randomly selected married couples --False here we cannot say paired as these people are not grouped under the same conditions.