Answer:
No he is not correct. As the answer would be -2/5 = -0.4 and 5/-2 = -2.5 as the answer is also not opposite.
 
        
                    
             
        
        
        
Answer:
a) Statistic.
b) The population proportion is expected to be between 0.29 and 0.31 with a 94% degree of confidence.
Step-by-step explanation:
a) The proportion of 30% is a statistic, as it is a value that summarizes data only from the sample taken in the study from USA Today. Other samples may yield different proportions.
b) We can use the statistic to estimate a confidence interval for the parameter of the population.
The standard error for the proportion is calculated as:

The margin of error is 0.01. We can use this value to determine the level of confidence that represents.
The formula for the margin of error is:

This z-value, according to the the standard normal distribution, corresponds to a confidence interval of 94%.
The interval for this margin of error is:

Then, we can conclude that the population proportion is expected to be between 0.29 and 0.31 with a 94% degree of confidence.
 
        
             
        
        
        
In 371 ways Mrs. Sullivan choose two  students from 27 to help put away calculators at  the end of class
Step-by-step explanation:
let us assume that Mrs.Sullivan  wants to choose 2 students from a group of 27 students
So ,in the first choice we have  27 students 
In the  second choice we have  26 choices
So Mrs.Sullivan has = 27 × 26 = 702 ways 
But  each group repeated twice,in order to avoid that we will divide the answer by 2
so we will write 
 = 702 ÷ 2 =<u> 351 ways</u>
<u>This method of calculation is called Combination</u>
 
        
             
        
        
        
Answer:
The probability that all the six people will test negative for the antibody is 0.9472.
The probability that the test comes back positive for at least one of the six people is 0.0528
Step-by-step explanation:
Consider the provided information.
probability that antibody is present will be effective is 99.1% and not present is 99.1% of the time.
Part (A)What is the probability that the test comes back negative for all six people? 
Let P(X)= P(Antibody not present)
We want test comes back negative for all six that means antibody is present for all six. Thus X=0

The probability that all the six people will test negative for the antibody is 0.9472.
Part (B) What is the probability that the test comes back positive for at least one of the six people?



Hence, the probability that the test comes back positive for at least one of the six people is 0.0528
 
        
             
        
        
        
Can u show the whole question