Answer:
Step-by-step explanation:
Given : A new catalyst is being investigated for use in the production of a plastic chemical. Ten batches of the chemical are produced. The mean yield of the 10 batches is 72.5% and the standard deviation is 5.8%. Assume the yields are independent and approximately normally distributed.
To find : A 99% confidence interval for the mean yield when the new catalyst is used ?
Solution :
Let X be the yield of the batches.
We have given, n=10 ,
, s=5.8%
Since the size of the sample is small.
We will use the student's t statistic to construct a 995 confidence interval.

From the t-table with 9 degree of freedom for 


The 99% confidence interval is given by,




<span> we have that
standard form of equation for parabola:
(x-h)^2=-4p(y-k)
(h,k) --------->being the (x,y) coordinates of the vertex.
Parabola opens downwards because focus is below vertex on the axis of symmetry.
For given problem:
</span><span>vertex: (-3,2)
axis of symmetry: x=-3
p=distance from vertex to focus on the axis of symmetry=2-(-1)=3
4p=12
Directrix: y=2+p=5
Equation:
(x+3)^2=-12(y-2)
the answer is </span>(x+3)^2=-12(y-2)
Answer:
5 and -5
Step-by-step explanation:
3x² = 75
x² = 75/3
x² = √25
x = 5 and - 5