Answer:
Function for given situation is : 
Value of computer after 4 years = $720.3.
Step-by-step explanation:
Given that the value of a $3000 computer decreases about 30% each year. Now we need to write a function for the computers value V(t). then we need to find about how much will the computer be worth in 4 years.
It clearly says that value decreases so that means function represents decay.
For decay we use formula:
where P=initial value = $3000,
r= rate of decrease =30% = 0.30
t= number of years
A=V(t) = future value
so the required function is 
or
Now plug t=4 years to get the value of computer after 4 years.
Hence final answer is $720.3.
4:5
explanation-
Express the given ratios as fraction
4 : 5 = 4/5 and 2 : 3 =2/3
Now find the L.C.M (least common multiple) of 5 and 3
The L.C.M (least common multiple) of 5 and 3 is 15.
Making the denominator of each fraction equal to 15, we have
4/5 = (4 ×3)/(5 ×3) = 12/15 and 2/3 = (2 ×5)/(3 ×5) = 10/15
Clearly, 12 > 10
Now, 12/15 > 10/15
Therefore, 4 : 5 > 2 : 3.
Answer: Y=-1
Explanation: 2y-3=y-4 (add three on both sides)
2y=y-1 (subtract y on both sides)
y=-1
Complete question:
Assume that different groups of couples use a particular method of gender selection and each couple gives birth to one baby this mention is designed to increase the likelihood that each baby will be a girl, but assume that the method has no effect so the probability of a girl is 0.5. Assume that the group consists of 36 couples.
A) Find the mean and standard deviation for the number of girls in groups of 36 births.
B) Use the range rule of thumb to find the values separating results that are significantly low and significantly high.
C) Is the result of 33 girls significantly high? A result of 33 girls would suggest the method is effective or is not effective?
Answer:
a) mean = 18
Standard deviation =3
b) low range = 12
High range = 24
c) The result of 33 girls is significantly high. Yes, the method is effective.
Step-by-step explanation:
Given:
p = 0.5
n = 36
a) The mean is the product of n and p
Mean u = np
u = 36 * 0.5 = 18
The standard deviation is the square root of the product of n and p&q.
S.d ó = 
b) To find the range rule of thumb:
• For low range
Low range = u - 2ó
= 18 - (2 * 3)
= 12
• High range
= u + 2ó
= 18 + (2*3)
= 24
c) The result is significantly high, because 33 is greater than 24 girls.
A result of 33 girls would prove the method as effective.
