Complete Question:
a) Is it plausible that X is normally distributed?
b) For a random sample of 50 such pairs, what is the (approximate) probability that the sample mean courtship time is between 100 min and 125 min?
Answer:
a) It is plausible that X is normally distributed
b) probability that the sample mean courtship time is between 100 min and 125 min is 0.5269
Step-by-step explanation:
a)X denotes the courtship time for the scorpion flies which indicates that is a real - valued random variable, and since normal distribution is a continuous probability distribution for a real valued random variable, it is plausible that X is normally distributed.
b) Probability that the sample mean courtship time is between 100 min and 125 min




From the probability distribution table:


Solution to equation
for all real values of x is
.
<u>Step-by-step explanation:</u>
Here we have ,
. Let's solve :
⇒ 
⇒ 
⇒ 
⇒ 
⇒ 
⇒ 
By quadratic formula :
⇒ 
⇒ 
⇒ 
⇒ 
⇒ 
⇒ 
But at
we have equation undefined as
. Hence only solution is :
⇒ 
Since , 
⇒ 
Now , General Solution is given by :
⇒ 
Therefore , Solution to equation
for all real values of x is
.
Answer:
1.05(0.85y)
Step-by-step explanation:
15% off so .85y and a 5% tax so 1.05(.85y)