Answer:
Step-by-step explanation:
We have the standard deviation for the sample, so we use the t-distribution 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 = 20 - 1 = 19
99% confidence interval
Now, we have to find a value of T, which is found looking at the t table, with 19 degrees of freedom(y-axis) and a confidence level of 
. So we have T = 2.861.
The margin of error is:
In which s is the standard deviation of the sample and n is the size of the sample.
The format of the confidence interval is:
In which 
is the sample mean
So
Answer:
Step-by-step explanation:
Ratios can be of 2 types here:
Part to Part
and
Part to Whole
Part-to-Part ratios give the relationship between 2 distinct things/groups. Such as the ratio of male to female in a class, or ratio of water to sugar in a drink etc.
Part-to-Whole ratios give the relationship between one group/thing to the whole population. Such as the ratio of male to total students in a class, or the ratio of cups of sugar to total cups of drinks etc.
<u>Note:</u> If there are 2 parts in a population, we can essentially write 3 ratios. For example, the ratio of male to female in a class is 4 to 5. So in total there are 4+5 = 9 parts (whole). So we can say:
ratio of male to total population is 4 to 9
ratio of female to total population is 5 to 9
Also,
ratio of male to female (as stated before) is 4 to 5
3 ratios.
Answer:
2
Step-by-step explanation:
(6+2)x 12 =96
Step-by-step explanation:
πrxrxh
3.14 x 3.5 x 3.5 x 10 = 384.65
3.14 x 2 x 2 x 6 = 75.36
Answer:
d=10
Step-by-step explanation: step 1: 2/5d-1 = 3/5d-3 add 3 to both sides
+3 +3
step 2: 2/5d+2 = 3/5d subtract 2/5d to both sides
-2/5d -2/5d
step 3: 2 = 1/5d multiply 5/1 to both sides
* 5/1 = *5/1
10 = d
