Answer:
2.87%
Step-by-step explanation:
We have the following information:
mean (m) = 200
standard deviation (sd) = 50
sample size = n = 40
the probability that their mean is above 21.5 is determined as follows:
P (x> 21.5) = P [(x - m) / (sd / n ^ (1/2))> (21.5 - 200) / (50/40 ^ (1/2))]
P (x> 21.5) = P (z> -22.57)
this value is very strange, therefore I suggest that it is not 21.5 but 215, therefore it would be:
P (x> 215) = P [(x - m) / (sd / n ^ (1/2))> (215 - 200) / (50/40 ^ (1/2))]
P (x> 215) = P (z> 1.897)
P (x> 215) = 1 - P (z <1.897)
We look for this value in the attached table of z and we have to:
P (x> 215) = 1 - 0.9713 (attached table)
P (x> 215) =.0287
Therefore the probability is approximately 2.87%
Answer:
<em>It takes them 1.875 hours.</em>
<em></em>
<em>Step-by-step explanation:</em>
<em></em>
<em>Here, the job is cleaning the house.</em>
<em></em>
<em>Mom does 1 job in 3 hours.</em>
<em></em>
<em>In 1 hour, mom does 1/3 of the job.</em>
<em></em>
<em>Dad does 1 job in 5 hours.</em>
<em></em>
<em>In 1 hour, dad does 1/5 of the job.</em>
<em></em>
<em>Mom and dad working together do the job in x hours.</em>
<em></em>
<em>In 1 hour, mom and dad together do 1/x of the job.</em>
<em></em>
<em>1/3 + 1/5 = 1/x</em>
<em></em>
<em>5/15 + 3/15 = 1/x</em>
<em></em>
<em>8/15 = 1/x</em>
<em></em>
<em>8x = 15</em>
<em></em>
<em>x = 15/8 = 1.875</em>
<em></em>
<em>Answer: It takes them 1.875 hours.</em>
your welcome
Answer:
$85
Step-by-step explanation:
445-20=425 425 ÷5= 85
No because any two sides have to add up to be more than the third side
2+8 is more than 6
8+6 is more than 2 but
2+6=8 so these can't make a triangle
Answer:
-47
Step-by-step explanation:
remove unnecessary parentheses
-4-44-(-1)
calculate the sum or different
-47