Sarah has two tests at school next week, a math test and a physics test. Let A represent the event that she passes her math test
1 answer:
Answer:
P(B)=0.7
Step-by-step explanation:
When the events do not affect each other, they are known as independent events. In other words, two events are independent if the outcome of the second event is not affected by the outcome of the first event.
If A and B are independent events, the probability that both events will occur is the product of the probabilities that the individual events will occur:
P(A and B)= P(A)*P(B)
In this case, P(A and B)= 0.21 and P(A)= 0.30
Replacing:
0.21=0.30*P(B)
Solving:
<u><em>0.7=P(B)</em></u>
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Answer:
E. -0.723
Since the p value is very high we don't have enough evidence to conclude that the true mean for the lengths is different from 6 cm.
Step-by-step explanation:
Information provided
represent the sample mean for the length
represent the sample standard deviation
sample size
represent the value that we want to test
represent the significance level
t would represent the statistic
represent the p value for the test
System of hypothesis
We need to conduct a hypothesis in order to check if the lathe is in perfect adjustment (6cm), then the system of hypothesis would be:
Null hypothesis:
Alternative hypothesis:
since we don't know the population deviation the statistic is:
(1)
Replacing in formula (1) we got:
E. -0.723
P value
The degrees of freedom are given by:
Since is a two tailed test the p value would be:
Since the p value is very high we don't have enough evidence to conclude that the true mean for the lengths is different from 6 cm.