Solve the problem.Within a group of n people, the number of possible handshakes, N, is given by N = 
(n2 - n). At a party, everybody shakes hands with every other person. If the total number of handshakes is 28, how many people are at the party?
A. 9
B. 10
C. 7
D. 8
Answer: D
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Indicate whether the function is one-to-one.C = {(6, 3), (9, 4), (7, 5), (5, 6)}
A. Yes B. No
Write the expression in lowest terms.
A. 1
B. -1
C. 
D. Cannot reduce
The normal distribution curve which models, distributions of data in a wide range of applications, is given by the function 
where 
and ? and ? are constants called the standard deviation and the mean, respectively. Its graph is shown in the figure.
?
?
In a survey, consumers were asked to rate a new toothpaste on a scale of 1-10. The resulting data are modeled by a normal distribution with 
and 
. The percentage of consumers who gave the toothpaste a score between a and b on the section is given by 
?
Use a Riemann sum with n = 10 to estimate the percentage of customers who rated the toothpaste 5 or higher. (Use the range 4.5 to 10.5.) Round your answer to the nearest whole number.
?
A. 45%
B. 46%
C. 47%
D. 48%
E. 49%
Plot the number 2.8 on the real number line.
A. 
B. 
C. 
D. 
E. 