Answer: 

Step-by-step explanation:
- A null hypothesis is a hypothesis where a researcher generally try to disprove, it says that there is no statistically significant relationship between the two variables .
- An alternative hypothesis says that there is a statistical significance between two variables.
Claim 1. : Mean age of online dating service users is 40 years.
i.e.
, since it has equals sign so we take this as null hypothesis.
Claim 2. : Mean age of online dating service users is not 40 years.
⇒ Null Hypothesis : 
Alternative hypothesis : 
70% is the same as 70/100 then we simplify by taking off one zero of each number 7/10 and we can't divide it any more so the answer is 7/10
Answer:

Step-by-step explanation:
Alvin takes pictures with his smartphone.
Of the pictures
are animals.
of the animals are dogs.
To find which fraction of all pictures are pictures with dogs, you can simply multiply two fractions:

<u>Another way</u> to solve this question:
Let the number of all pictures be 24 (divisible by both 4 and 6).
Then the number of pictures with animals is

and the number of pictures with dogs is

Hence, the fraction of pictures with dogs of all pictures is

Answer:

Step-by-step explanation:
Hello!
We can use the special binomial product formulas:
<h3>Simplify</h3>
The simplified form is 
Point slope form is just a point and the slope written in the form y-y1 =m (x-x1).
Where x1 and y1 (should be subscripts) are (x1,y1) the point you are given.
So in this case all you must do is plug in the given values:
( y-y1 ) = m ( x-x1 )
( y-4. ) = -1 ( x-2 )
This being your answer
I hope this helps!!