5 out of 20 cars are red
Therefore 1 out of 4 cars is red
1/4 of cars are red
1/4 x 100 = 25 red cars
Answer:
40 mph
Step-by-step explanation:
40 mins to bike usually, which means he bikes 10 miles. He needs to bike at a minimum of 10 miles in 15 mins, which translates to 40 miles in an hour.
P.S. He is going to surely be late.
Answer:
The margin of error for the 95% confidence interval for the mean score of all such subjects is of 8.45.
Step-by-step explanation:
We have the standard deviation for the sample, which means that the t-distribution is used to solve this question.
The first step to solve this problem is finding how many degrees of freedom, we have. This is the sample size subtracted by 1. So
df = 27 - 1 = 26
95% confidence interval
Now, we have to find a value of T, which is found looking at the t table, with 26 degrees of freedom(y-axis) and a confidence level of . So we have T = 2.0518
The margin of error is:
In which s is the standard deviation of the sample and n is the size of the sample.
In this question:
. So
The margin of error for the 95% confidence interval for the mean score of all such subjects is of 8.45.