Considering that we have the standard deviation for the sample, the t-distribution will be used, and the critical value is t = 2.6682.
<h3>When should the t-distribution and the z-distribution be used?</h3>
- If we have the standard deviation for the sample, the t-distribution should be used.
- If we have the standard deviation for the population, the z-distribution should be used.
In this problem, σ is not known, hence we get the standard deviation of the sample from the histogram and the t-distribution is used.
Using a t-distribution calculator, considering a <em>confidence level of 99%</em> and 56 - 1 = <em>55 df</em>, the critical value is t = 2.6682.
More can be learned about the t-distribution at brainly.com/question/16162795
Answer:
x=19º
x+9=28º
7x=133º
Step-by-step explanation:
x+9+x+7x=180
9x+9=180
9x=180-9
9x=171
x=19
Answer:
Step-by-step explanation:
Recall what the relationship between cosine and secant:
In other words, secant is the reciprocal of cosine.
So, if we know cosine, we only need to find its reciprocal to find secant.
We are given that cosine is:
Then secant must be:
So:
Square:
And we're done!
Answer:
Evelyn's dance class on Saturday starts at 11:05 A.M.
Step-by-step explanation:
I know this because if her class takes an hour and 40 minutes you would subtract the hour and 40 minutes from 12:45 so you could do 12 - 1 which equals 11. Then you would do 45 - 40 which equals 5. And last you would put the new times together so it would be, 11:05. Her dance class starts at 11:05 A.M.
