Answer:
7.25
Step-by-step explanation:
Given :
___________ Sample size __ sample mean
Treatment 1 ____ 5 _______ 4
Treatment 2 ____ 10 ______ 8
Treatment 3 ____ 5 _______ 9
Sample size = (5 + 10 + 5). = 20
Overall mean = ((5*4). + (10*8) + (5*9)) / 20
Overall mean = (20 + 80 + 45) / 20
= 145 / 20
= 7.25
Answer:
Yes
Step-by-step explanation:
16 ÷ 3 = 5.333333...
Answer: C
Step-by-step explanation:it’s the 3rd ans on edge
The answer to the question is -24
Answer:
The standard deviation of weight for this species of cockroaches is 4.62.
Step-by-step explanation:
Given : A different species of cockroach has weights that are approximately Normally distributed with a mean of 50 grams. After measuring the weights of many of these cockroaches, a lab assistant reports that 14% of the cockroaches weigh more than 55 grams.
To find : What is the approximate standard deviation of weight for this species of cockroaches?
Solution :
We have given,
Mean 
The sample mean x=55
A lab assistant reports that 14% of the cockroaches weigh more than 55 grams.
i.e. P(X>55)=14%=0.14
The total probability needs to sum up to 1,



The z-score value of 0.86 using z-score table is z=1.08.
Applying z-score formula,

Where,
is standard deviation
Substitute the values,





The standard deviation of weight for this species of cockroaches is 4.62.