Answer:
The number of once is 9.1
The number of hundreds is 8.9
Step-by-step explanation:
Given as :
The total of digits having ones and hundreds = 900
The sum of digits = 18
Let The number of ones digit = O
And The number of hundreds digit = H
So, According to question
H + O = 18 .........1
100 × H + 1 × O = 900 ........2
Solving the equation
( 100 × H - H ) + ( O - O ) = 900 - 18
Or, 99 H + 0 = 882
Or , 99 H = 882
∴ H = 
I.e H = 8.9
Put the value of H in eq 1
So, O = 18 - H
I.e O = 18 - 8.9
∴ O = 9.1
So, number of once = 9.1
number of hundreds = 8.9
Hence The number of once is 9.1 and The number of hundreds is 8.9
Answer
Answer:
0.0266, 0.9997,0.7856
Step-by-step explanation:
Given that the IQs of university​ A's students can be described by a normal model with mean 140 and standard deviation 8 points. Also suppose that IQs of students from university B can be described by a normal model with mean 120 and standard deviation 11. Let x be the score by A students and Y the score of B.
A)
B) Since X and Y are independent we have
X-Y is Normal with mean = 140-120 =20 and 

C) For a group of 3, average has std deviation = 

Answer:
D sentence 5
Step-by-step explanation:
The normal distribution curve is shown in the diagram below
<span>The percentage of time that his commute time exceeds 61 minutes is equal to the area under the standard normal curve that lies to the RIGHT of X=61
Standardising X=61 to find z-score
</span>

<span>
from the z-table
</span>

<span>
</span>