Her method will produce a valid sample.
Her method will produce a random sample.
Her method will produce a representative sample.
Answer:
The required probability is 0.988.
Step-by-step explanation:
Consider the provided information.
Based on a poll, 67% of Internet users are more careful about personal information when using a public Wi-Fi hotspot.
That means the probability of more careful is 0.67
The probability of not careful is: 1-0.67 = 0.33
We have selected four random Internet users. we need to find the probability that at least one is more careful about personal information.
P(At least one careful) = 1 - P(None of them careful)
P(At least one careful) = 1 - (0.33×0.33×0.33×0.33)
P(At least one careful) = 1 - 0.012
P(At least one careful) = 0.988
Hence, the required probability is 0.988.
The result may be higher because of the convenience bias in retrieving the sample. Because the survey subjects volunteered to respond not random.
Answer: False, there are actually 900 different three-digit numbers
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Explanation:
The three digit numbers span from 100 to 999, including both endpoints.
This means we have 999-100+1 = 900 different three-digit numbers.
You subtract the endpoints (large-small) and add 1 to include the lower endpoint.
Here's a smaller example of why this works: say you had the set {1,2,3,4} and we wanted to count the number of items in this set. Clearly there are 4 items. Note how subtracting the endpoints 4-1 gets us 3 instead, so we add on 1 to include that left endpoint.
Answer:
From $1600 to $3400.
Step-by-step explanation:
The Empirical Rule states that, for a normally distributed random variable:
68% of the measures are within 1 standard deviation of the mean.
95% of the measures are within 2 standard deviation of the mean.
99.7% of the measures are within 3 standard deviations of the mean.
In this problem, we have that:
Mean = 2500
Standard deviation = 300
What interval of dealer incentives would we expect approximately 99.7% of vehicles to fall within?
By the Empirical Rule, 99.7% fall within 3 standard deviations frow the mean. So
From 2500 - 3*300 = 1600 to 2500 + 3*300 = 3400.
