Answer: 

Step-by-step explanation:
We know that mean and standard deviation of sampling distribution is given by :-


, where
= population mean
=Population standard deviation.
n= sample size .
In the given situation, we have
n= 2
Then, the expected mean and the standard deviation of the sampling distribution will be :_

[Rounded to the nearest whole number]
Hence, the the expected mean and the standard deviation of the sampling distribution :


Surface area of a sphere = <span>4π<span>r2</span></span>
the volume of a sphere= <span><span>43</span>π<span>r3</span></span>
so <span>5000π=<span>4/3</span><span>πr3
</span></span><span>> r^3 = 5000 x 3 / 4
=>
r^3 = 3750
</span>taking cube root on both sides
r=15.53616
hope it helps
Ok so let me help you like this: We need to understand first that <span>The basketball has a higher speed, that means that the tennis ball will never catch up. so what we need to use is the formula
</span>Vr=Vb--Vt
<span>=0.5-0.25=0.25
</span>So the speed is <span>0.25m/s
Hope this is useful</span>
Answer:
At least 832 teenargers must be interviewed.
Step-by-step explanation:
We have that to find our
level, that is the subtraction of 1 by the confidence interval divided by 2. So:
Now, we have to find z in the Ztable as such z has a pvalue of
.
So it is z with a pvalue of
, so
Now, find the margin of error M as such
In which
is the standard deviation of the population and n is the size of the sample.
How many teenagers must the firm interview in order to have a margin of error of at most 0.1 liter when constructing a 99% confidence interval
At least n teenargers must be interviewed.
n is found when M = 0.1.
We have that 
So




Rounding up
At least 832 teenargers must be interviewed.
Answer: b. 0.8413
Step-by-step explanation:
Given : The average time taken to complete an exam, X, follows a normal probability distribution with
and
.
Then, the probability that a randomly chosen student will take more than 30 minutes to complete the exam will be :-
[using z-value table]
Hence, the probability that a randomly chosen student will take more than 30 minutes to complete the exam = 0.8413