Answer:
x=7
Step-by-step explanation:
 
        
             
        
        
        
Using the binomial distribution, it is found that there is a 0.4096 = 40.96% probability that he answers exactly 1 question correctly in the last 4 questions.
<h3>What is the binomial distribution formula?</h3>
The formula is:


The parameters are:
- x is the number of successes.
- n is the number of trials.
- p is the probability of a success on a single trial.
Considering that there are 4 questions, and each has 5 choices, the parameters are given as follows:
n = 4, p = 1/5 = 0.2.
The probability that he answers exactly 1 question correctly in the last 4 questions is P(X = 1), hence:


0.4096 = 40.96% probability that he answers exactly 1 question correctly in the last 4 questions.
More can be learned about the binomial distribution at brainly.com/question/24863377
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If Erica earned a total of $15450 last year from both the jobs then he earns $2840 from college if she earned 1250 more than four times the amount from college from store.
Given Total amount earned=$15450,Amount earned from store is 1250 more than 4 times earned from college.
Amount from store forms an equation.
let the amount earned from college is x.
According to question:
Amount earned from store=4x+1250
Amount earned from college=x
Total amount earned=4x+1250+x
5x+1250=15450
5x=15450-1250
5x=14200
x=14200/5
x=2840
Put the value of x in 4x+1250 to get amount earned from store=4(2840)+1250=$12610.
Hence the amount earned by Erica from college is $2840.
Learn more about equation at brainly.com/question/2972832
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42000000000000000
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