Answerwhat do you need help with?
Step-by-step explanation:
Her average in first three test = 89
This means, her total scores in first three test were = 3 x 89 = 267
Her average in four tests = 91
This means, her total scores in four tests are = 364
267 give the sum of first three test scores. and 364 give the sum of scores with fourth test adding in three tests.
So, subtracting 267 from 364 will give us the scores of Fourth test.
Scores of Fourth test = 364 - 267 = 97
Thus, Samantha's Claim is correct
Answer:0.92
Step-by-step explanation:
Given
of Population is vaccinated
So, Probability of a person being vaccinated is 
and simultaneously , probability of not vaccinated is 

Now, Probability that atleast one of them has been vaccinated is given by



The answer is 4
This is because |-5+9|=|-4| which equals 4