Answer:
95% two-sided confidence interval on the true mean breaking strength is (94.8cm, 99.2cm)
Step-by-step explanation:
Our sample size is 11.
The first step to solve this problem is finding our degrees of freedom, that is, the sample size subtracted by 1. So
.
Then, we need to subtract one by the confidence level
and divide by 2. So:

Now, we need our answers from both steps above to find a value T in the t-distribution table. So, with 10 and 0.025 in the two-sided t-distribution table, we have 
Now, we find the standard deviation of the sample. This is the division of the standard deviation by the square root of the sample size. So

Now, we multiply T and s
cm
For the upper end of the interval, we add the sample mean and M. So the upper end of the interval here is
cm
So
95% two-sided confidence interval on the true mean breaking strength is (94.8cm, 99.2cm).
To find the fraction of the grouo that passed both exams, we need to first convert 75% into a fraction:
75%
=75/100
=3/4
We can then mutiply the fraction above by the students who passed the psychological exam:
3/4×3/5
=9/20
Therefore the answer is 9/20.
Hope it helps!
Answer:
21+4
Step-by-step explanation:
3 times 7=21
3 times4=12
21d+4e
Answer:
30/182 = 15/91.
Step-by-step explanation:
<u>PROBABILITY:</u> the likelihood of an event.
There are a total of 14 shirts in the basket.
Of the 14, 8 (8/14) of them are white, and 6 (6/14) of them are black.
The probability of picking a black shirt is 6 in 14, or 6/14.
The probability of picking a white shirt is 8 in 14, or 8/14.
<u>WITHOUT REPLACING:</u> This means that you take one without putting it back. (There will be one less).
6/14 × 5/13 = 30/182.
30/182 = 15/91.
62 - 4 = 58
58 / 2 = 29
The width is 29.