Answer:
The critical value is T = 1.895.
The 90% confidence interval for the mean repair cost for the washers is between $48.159 and $72.761
Step-by-step explanation:
We have the standard deviation for the sample, so we use the t-distribution.
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 = 8 - 1 = 6
90% confidence interval
Now, we have to find a value of T, which is found looking at the t table, with 6 degrees of freedom(y-axis) and a confidence level of
. So we have T = 1.895, which is the critical value.
The margin of error is:

In which s is the standard deviation of the sample and n is the size of the sample.
The lower end of the interval is the sample mean subtracted by M. So it is 60.46 - 12.301 = $48.159
The upper end of the interval is the sample mean added to M. So it is 60.46 + 12.301 = $72.761
The 90% confidence interval for the mean repair cost for the washers is between $48.159 and $72.761
A girl has 20 marbles
10 are red, 7 are blue, and 3 are green
If she picks 5 marbles, without replacing them, what are the chances all 5 are red?
10/20 * 9/19 * 8/18 *7/17 * 6/16
1/2 * 9/19 * 4/9 * 7/17 * 3/8
1/2 * 1/19 * 3/2
1/76
<u>Answer:</u>
The experimental probability is 3% greater than the theoretical probability.
<u>Step-by-step explanation:</u>
We are given the results of flipping two coins with their outcomes and number of times they were tossed.
We are to compare the experimental and theoretical probability of getting HH.
The theoretical Outcomes are: HH HT TH TT
So theoretical probability of getting HH =
= 25%
Total number of outcomes =
= 100
So experimental probability of getting HH =
= 28%
Therefore, the experimental probability is 3% greater than the theoretical probability.