Answer: About 191 students scored between a 60 and an 80.
Step-by-step explanation:
Given : A set of 200 test scores are normally distributed with a mean of 70 and a standard deviation of 5.
i.e.
and 
let x be the random variable that denotes the test scores.
Then, the probability that the students scored between a 60 and an 80 :

The number of students scored between a 60 and an 80 = 0.9544 x 200
= 190.88 ≈ 191
Hence , about 191 students scored between a 60 and an 80.
The equation of the parallel line is y = –2x – 11.
Solution:
Given equation of the line is y = –2x – 5.
Slope of this line is
= –2
To write the equation parallel to this line and passes through (–4, –3).
<em>If two lines are parallel, then they have the same slope.</em>


<u>Point-slope formula:</u>

Substitute the given values in the formula, we get



Subtract 3 from both sides of the equation.


Hence the equation of the parallel line is y = –2x – 11.
Answer:
zero
Step-by-step explanation:
5x+10 = 5x-8
5x-5x = -8-10
0 = -18
so zero
Answer:
32%
Step-by-step explanation:
<h3>Given that:</h3>
- Jackie is saving money to buy a new cell phone.
- The cell phone costs $175
- she has already saved $56
<h3>To find:</h3>
- The percent of the cost of the cell phone has Jackie saved
In order to find the percent of the cost of the cell phone has Jackie saved,
- divide the cost of the cell phone by the amount of the money Jackie saved
- Multiply the result (1) by 100
See below how it's done:

dividing yields:

multiplying yields:

Alternative:
Instead of dividing,we can consider reducing the fraction and multiply that with 100 to get the answer.

In conclusion:
Jackie has saved 32% of the cost of the cell phone
Answer:
Integers, whole numbers and polynomials are sets of closed under multiplication.
Only Irrational numbers are not the sets of closed under multiplication.
Step-by-step explanation:
To find : Which of the following sets are closed under multiplication?
1. Integers
Yes, integers is a sets of closed under multiplication as if you multiply an integer by an integer, you will always get another integer.
Example -
is an integer
2. Irrational numbers
No, irrationals are not closed under multiplication.
Example -
is a rational number
3. Whole numbers
Yes, whole numbers is a sets of closed under multiplication as if you multiply a whole number by a whole number, you will always get another whole number.
Example -
is a whole number
4. Polynomials
Yes, polynomial is sets of closed under multiplication as if you multiply the variables' exponents are added, and the exponents in polynomials are whole numbers so the new exponents will be whole numbers.
Example -
is a polynomial.