One number is 6 times a first number. A third number is 100 more than the first number. If the sum of the three numbers is580 ,
1 answer:
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Answer:
A sample of 1077 is required.
Step-by-step explanation:
In a sample with a number n of people surveyed with a probability of a success of , and a confidence level of
, we have the following confidence interval of proportions.
In which
z is the zscore that has a pvalue of .
The margin of error is of:
42% of freshmen do not visit their counselors regularly.
This means that
98% confidence level
So , z is the value of Z that has a pvalue of
, so
.
How large of a sample size is required?
A sample size of n is required, and n is found when M = 0.035. So
Rounding up:
A sample of 1077 is required.
Answer:
(b)0.56
(c)0.38
Step-by-step explanation:
(a)
P(Ben Pass) =0.8
Therefore: P(Ben fails)=1-0.8 =0.2
P(Tom Pass) =0.7
Therefore: P(Tom fails)=1-0.7 =0.3
See attached for the completed tree diagram
(b)Probability that both will pass
P(both will pass)=P(Ben pass and Tom pass)
=P(Ben pass) X P(Tom pass)
=0.8 X 0.7
=0.56
(c)The probability that only one of them will pass
Since either Tom or Ben can pass, we have:
P(only one of them will pass)
=P(Ben pass and Tom fails OR Ben Fails and Tom Pass)
=P(Ben pass and Tom fails)+P(Ben Fails and Tom Pass)
=(0.8 X 0.3) + (0.2 X 0.7)
=0.24 + 0.14
=0.38
