Answer:
11/20
Step-by-step explanation:
At the beginning, the number of marbles in the box are:
10 green marbles
11 white marbles
The first marble chosen is green, and then it is not replaced in the box. Therefore, the number of green marbles left in the box is 9.
Therefore, the total number of marbles left in the box is:
Now we want to find the probability to choose a white marble. The number of white marble is
Therefore, the probability of choosing a white marble is:
Given Information:
Mean time to finish 400 meter dash = μ = 65 seconds
Standard deviation to finish 400 meter dash = σ = 2.5 seconds
Confidence level = 95%
Required Information:
95% confidence interval = ?
Answer:
Step-by-step explanation:
In the normal distribution, the empirical rule states approximately 68% of all the data lie within 1 standard deviation from the mean, approximately 95% of all the data lie within 2 standard deviations from the mean and approximately 99.7% of all the data lie within 3 standard deviations from the mean.
The confidence interval for 95% confidence limit is given by
Since approximately 95% of all the data lie within 2 standard deviations from the mean. μ is the mean time Carson takes to finish 400 meter dash and σ is the standard deviation.
Therefore, the 95% confidence interval is between 60 to 70 seconds
What does it mean?
It means that we are 95% confident that the Carson's mean to finish 400 meter dash is within the interval of (60, 70).