Answer:
42
Step-by-step explanation:
7 times 3 is 21
21 is half of 42
Y * 10 = z
y = dollars
z = dimes
4 dollars = 4y
Replace y with 4:
4* 10 = 40.
The total amount of dimes in 4 dollars is 40 dimes.
Hope this helped☺☺
Answer:
85%
Step-by-step explanation:
The discount is 15% which we can write as 0.15 and we multiply that by 30 to get the discount, which is $4.50. We subtract that from the original price; 30 to get $25.50 as the sale price. We want to find out what percent of 30 25.50 is, so we divide 25.50 and 30 to get 0.85. Multiply that by 100 to get 85%.
Answer and Explanation:
Given : The random variable x has the following probability distribution.
To find :
a. Is this probability distribution valid? Explain and list the requirements for a valid probability distribution.
b. Calculate the expected value of x.
c. Calculate the variance of x.
d. Calculate the standard deviation of x.
Solution :
First we create the table as per requirements,
x P(x) xP(x) x² x²P(x)
0 0.25 0 0 0
1 0.20 0.20 1 0.20
2 0.15 0.3 4 0.6
3 0.30 0.9 9 2.7
4 0.10 0.4 16 1.6
∑P(x)=1 ∑xP(x)=1.8 ∑x²P(x)=5.1
a) To determine that table shows a probability distribution we add up all five probabilities if the sum is 1 then it is a valid distribution.


Yes it is a probability distribution.
b) The expected value of x is defined as

c) The variance of x is defined as

d) The standard deviation of x is defined as



Take the -3/5 and add it to 1/30 which would equal 19/30, so x= 19/30