Let 
be the random variable for the number of marks a given student receives on the exam.
10% of students obtain more than 75 marks, so
where 
follows a standard normal distribution. The critical value for an upper-tail probability of 10% is
where 
denotes the CDF of , and 
denotes the inverse CDF. We have
Similarly, because 20% of students obtain less than 40 marks, we have
so that
Then 
are such that
and we find
Answer and explanation:
<em>To solve this, you must find what x equals</em>
x + 2x + 7 = 3x - 7 <em>Add together any numbers that can be added on their side</em>
3x + 7 = 3x - 7 <em>Then subtract 7 from both sides to get 3x alone</em>
3x = 3x - 14 <em> Then subtract 3x from both sides to get x</em>
<h3><em>*The x's cancel each other out so you must have typed the equation wrong. Please check to see any mistakes you may have made*</em></h3>
Answer:
(7/4)(2)(2)=7
Step-by-step explanation:
Answer:
Step-by-step explanation:
To find the population density of any state:
We must divide the population number by the area
Thus Washington state's population density equals 7,705,281 / 71297.95
Which equals 108.1
Hope that helps!
