Step-by-step explanation:
his father's age= 4x
his mother's age= 4x- 7
his age= x
x+4x+4x-7=101
x+ 4x+ 4x= 101+ 7
9x= 108
= 
x= 12
Tesfa is 12 years old
Answer:
Standard error = 0.4
Step-by-step explanation:
Step 1
We find the Standard Deviation
The formula = √(x - mean)/n - 1
n = 15
Mean = 1.93 hours
= √(0- 1.93)² + (0-1.93)² +(0- 1.93)²+( 0- 1.93)²+ (1- 1.93)² + (1- 1.93)² +(1 - 1.93)² +(2 - 1.93)² + (2 - 1.93)² + (2 - 1.93)² + (2 - 1.93)² + ( 2 - 1.93)² +(4 - 1.93)² +(4 - 1.93)² + (5 - 1.93)²/15 - 1
= √(3.737777776 + 3.737777776 + 3.737777776 + 0.871111111 +0.871111111 + 0.871111111 + 0.004444444445+ 0.004444444445 + 0.004444444445 + 0.004444444445 + 0.004444444445 + 1.137777778 + 4.271111112 + 4.271111112 + 9.404444446)/15 - 1
= √2.352380952
= 1.533747356
Step 2
We find the standard error
The formula = Standard Deviation/√n
Standard deviation = 1.533747356
n = 15
= 1.533747356/√15
= 1.533747356 /3.87298334621
= 0.39601186447
Approximately = 0.4
Therefore, the standard error is 0.4
Answer:
option a or c
Step-by-step explanation:
hope it helps u
State the given in the question
Given that the sum of a number and 3 is subtracted from, the result is 5
State what is to be found in the question
We are to find the number. In other to achieve this, we would follow the steps below:
Step 1: Represent the number with an unknown
Let x represent the number
Step 2: Interpret the given statement mathematically
If x is the number, then the sum of the number and 3 would be

Then the sum of a number and 3 subtracted from 10 would be

Finally, when the sum of a number and 3 subtracted from 10, the result is 5, would be

Step 3: Solve for x in the mathematical interpretation of the given statement
The value of x is as calculated as shown below:

Hence, the number is 5
Answer:
Bb
Step-by-step explanation: