Amount after 3 years = 4000( 1 + 0.04)^3 = $4,499.46 answer
(a) From the histogram, you can see that there are 2 students with scores between 50 and 60; 3 between 60 and 70; 7 between 70 and 80; 9 between 80 and 90; and 1 between 90 and 100. So there are a total of 2 + 3 + 7 + 9 + 1 = 22 students.
(b) This is entirely up to whoever constructed the histogram to begin with... It's ambiguous as to which of the groups contains students with a score of exactly 60 - are they placed in the 50-60 group, or in the 60-70 group?
On the other hand, if a student gets a score of 100, then they would certainly be put in the 90-100 group. So for the sake of consistency, you should probably assume that the groups are assigned as follows:
50 ≤ score ≤ 60 ==> 50-60
60 < score ≤ 70 ==> 60-70
70 < score ≤ 80 ==> 70-80
80 < score ≤ 90 ==> 80-90
90 < score ≤ 100 ==> 90-100
Then a student who scored a 60 should be added to the 50-60 category.
Answer: The refrigerator cost in this month is $4.5 approximately.
Step-by-step explanation:
Since we have given that
Amount of watt of electric power = 320 W
Number of days = 30
Unit cost of electricity = $0.13/Kwh
Hold factor = 
Number of hours in a month = 24
So, the refrigerator cost in this month would be

Hence, the refrigerator cost in this month is $4.5 approximately.
I think it is D but i am not too sure
Answer:
(-4, 0) U (1, ∞)
Step-by-step explanation:
Set each factor EQUAL to zero to find the zeroes (since it is not actually equal to zero, you will use an open circle when graphing and an open bracket when writing in interval notation).
x = 0 x-1 = 0 x + 4 = 0
x = 1 x = -4
Next, choose a value to the far left, between each of the zeroes, and to the far right to evaluate if it makes a true statement when input into the given inequality.
far left (I choose -5): -5(-5 - 1)(-5 + 4) > 0 → (-)(-)(-) > 0 → negative > 0 FALSE
- 4 to 0 (I choose -2): -2(-2 - 1)(-2 + 4) > 0 → (-)(-)(+) > 0 → positive > 0 TRUE
0 to 1 (I choose 0.5): .5(.5 - 1)(.5 + 4) > 0 → (+)(-)(+) > 0 → negative > 0 FALSE
far right (I choose 2): 2(2 - 1)(2 + 4) > 0 → (+)(+)(+) > 0 → positive > 0 TRUE