I mean it would be A and D because I don't know why they are both the same answer. If 10 books were sold yesterday, at LEAST 20 are needed to make the goal.
There are two choices for each child: overweight (o) or underweight (u). So if the first child is o the next can be o or u. If the first is u the second can be o or u. This gives four possibilities. Here the first child is the letter noted first and the second is the one listed second:
OO
OU
UO
UU
There are 4 outcomes and if each is equally likely then the probability of each is 1/4. Thus the probability of UU is 1/4
The probability of one underweight and one over weight is 1/2 because in two of the outcomes listed above there is one O and one U (namely OU and UO). Since there are 4 outcomes the probability is 2/4 = 1/2
Ed has $37 and decides that he wants to go out to lunch with his friend Barb. They go out to eat, and when it comes time to pay the bill they decide to split it. It will cost Ed $12 to pay his half. How much money will he have left after he pays his share?
Answer:
2.42
Step-by-step explanation:
standard deviation= sqrt(variance)
Variance=E[X2] - E[X]2
E[X] = sum(X)/n=35/9, so E[X]2 = 1225/81
E[X2] =sum(X2)/n = 189/9 = 170/81
Variance= 476/81
Standard deviation = sqrt(476/81) ~2.42
Answer:
38.11%
Step-by-step explanation:
Given that:
Mean (μ) = 75, standard deviation (σ) = 5
Z score is a measure in statistics to determine the variation of a raw score from the mean. It is given by the equation:

To calculate the percentage of students scored between a 73 and 78 (C grade), we need to find the z score for 73 and then for 78.
For x = 73, the z score is:

For x = 78, the z score is:

From the probability distribution table:
P(73 < x < 78) = P(-0.4 < z < 0.6) = P(z < 0.6) - P(z < -0.4) = 0.7257 - 0.3446 = 0.3811 = 38.11%