Answer:

Step-by-step explanation:
we are given half-life of PO-210 and the initial mass
we want to figure out the remaining mass <u>after</u><u> </u><u>4</u><u>2</u><u>0</u><u> </u><u>days</u><u> </u>
in order to solve so we can consider the half-life formula given by

where:
- f(t) is the remaining quantity of a substance after time t has elapsed.
- a is the initial quantity of this substance.
- T is the half-life
since it halves every 140 days our T is 140 and t is 420. as the initial mass of the sample is 5 our a is 5
thus substitute:

reduce fraction:

By using calculator we acquire:

hence, the remaining sample after 420 days is 0.625 kg
7+13+1.5=21.5
If he did it again the way back, it's 21.5 times 2.
He went a total of 43 blocks.
Answer:
The dependent variable is the final grade in the course and is the vriable of interest on this case.
H0: 
H1: 
And if we reject the null hypothesis we can conclude that we have a significant relationship between the two variables analyzed.
Step-by-step explanation:
On this case w ehave the following linear model:

Where Y represent the final grade in the course and X the student's homework average. For this linear model the slope is given by
and the intercept is 
Which is the dependent variable, and why?
The dependent variable is the final grade in the course and is the vriable of interest on this case.
Based on the material taught in this course, which of the following is the most appropriate alternative hypothesis to use for resolving this question?
Since we conduct a regression the hypothesis of interest are:
H0: 
H1: 
And if we reject the null hypothesis we can conclude that we have a significant relationship between the two variables analyzed.
Answer:
25 units
Step-by-step explanation:
Applying Pythagoras' Theorem,
(BD)^2= (CD)^2 + (BC)^2
(BC)^2= 65^2 - 60^2
(BC)^2= 625
BC= √625= 25