Cho hai biến cố xung khắc và B, sao cho ( ≠ 0), ( ≠ 0). Hỏi A và B có độc lập không?
1 answer:
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<h3>Question:</h3>
<em>Jon is selling tickets for the school talent show. On the 1st day, he sold 3 senior tickets and 12 child tickets for $195. On the 2nd day he sold 13 senior tickets for $299. Find the price of a senior citizen ticket.</em>
<h3>Answer:</h3>- $23
Create a system of equations to help you solve this problem. The system of equations will look like: 3s + 12c = 195 and 13s = 299. The variable s represents the cost of senior tickets and the variable c represents the cost of children tickets.
Solve the second equation for the variable s as this is the easiest way to solve the problem. Solve the second equation for s by dividing both sides of the equation by 13 to isolate the variable s.
s = 23
Since the question was only asking for the price of a senior citizen ticket, you are technically done. The first equation was only put there to confuse you or allow you to check your work if you needed to. The price of a senior citizen ticket (variable s) is $23.
Answer:
There is no enough evidence to support the claim that the proportion of US teens that have some level of hearing loss differs from 20%.
P-value=0.12
Step-by-step explanation:
We have to perform a test of hypothesis on the proportion.
The claim is that the proportion of US teens that have some level of hearing loss differs from 20%.
Then, the null and alternative hypothesis are:
The significance level is assumed to be 0.05.
The sample, of size n=1981, has 369 positive cases. Then, the proportion is:
The standard error of the proportion is:
Now, we can calculate the statistic z:
The P-value for this two-tailed test is:
The P-value is below the significance level, so the effect is not significant. The null hypothesis failed to be rejected.
There is no enough evidence to support the claim that the proportion of US teens that have some level of hearing loss differs from 20%.