Answer:
40% of the class is Girls, so 12 students are girls
Step-by-step explanation:
add up the ratio
2+3=5
divide by 5
30/5=6
multipy ratio to find totial number of students
2*6=12
2*3=18
divide the number of students to get the pecentage
12/30=0.4=40%
18/30=0.6=60%
Answer:
9 x 7 = 63 is cost of 9 people
3 x 9
6 x 8
8 x 8
9 x 7
Part A: First, list multiples for each number. The multiples of 5 are: 5, 10, 15, 20, 25 30, 35, 40, 45, 50, 55, 60, etc. The multiples of 12 are: 12, 24, 36,48, 60, etc. The least common multiple is the first common multiple between the two, in this case being 60. The LCM of 5 and 12 is 60.
Part B: SImilar to above, list all factors for each number. 72: 1, 2, 3, 4, 6, 8, 9, 12, 18, 24, 36, and 72. 81: 1, 3, 9, 27, and 81. The greatest common factor is the highest common number, 9 in this case. The GCF of 72 and 81 is 9.
Part C: To rewrite, we need to take out the 9 by dividing. 72/9 is 8. 81/9 is 9. Therefore, we would get 9(8+9), to equal 153. Your answer here is 9( 8 + 9 ). Hope this helped!
Answer:
1a

1b
95% of all sample means will fall between 
1c

2

Step-by-step explanation:
From the question we are told that
The mean is 
The population standard deviation is 
The sample size is n = 16
Generally the standard error of the mean is mathematically represented as

=> 
=> 
Generally the probability that the sample mean will be between 39 and 48 minutes is
=> 
=> 
From the z table the area under the normal curve to the left corresponding to 1.2 and -2.4 is
=> 
and

So

=> 
From the question we are told the confidence level is 95% , hence the level of significance is

=> 
Generally from the normal distribution table the critical value of is

Generally the margin of error is mathematically represented as

=>
=>
Generally the 95% of all sample means will fall between

=> 
Generally the value which 90% of sample means is greater than is mathematically represented

=> 
=> 
Generally from the z-table the critical value of 0.90 is


=> 
Considering question 2
Generally we are told that the standard deviation of the mean to be one fifth of the population standard deviation, this is mathematically represented as

Generally the standard deviation of the sample mean is mathematically represented as

=> 
=> 
=> 