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
CAN ANYONE HELP ME WITH THIS PLSSSSSSSSSSSSSSS
1 answer:
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Answer:
8
Step-by-step explanation:
× 8
= 3
In algebra:
× y = 3
y = 3 ÷
y = 8
Answer:
a. 28.8
Step-by-step explanation:
Using the theorem of similarity, the following equation can be generated:
Solve for x
Cross multiply
Divide both sides by 25
x = 28.8
Answer:
a. The sample size is approximately 97 adults
Step-by-step explanation:
The given parameters are;
The number of adults surveyed, n = 174
The lowest value of the pulse rate = 39 bpm
The highest value of the pulse rate = 111 bpm
The level of confidence used for determining the sample size = 90%
The given sample mean = 3 pm of the population mean
a. The range rule of thumb states that the standard deviation is approximately one quarter (1/4) of the range
The range = 111 bpm - 39 bpm = 72 bpm
Therefore, the standard deviation, σ = 72 bpm/4 = 18 bpm
The sample size, 'N', is given as follows;
Where;
N = The sample size
z = The confidence level, 90% (z-score at 90% = 1.645)
p·q = σ² = 18² = 324
e² = 3² = 9
Therefore the appropriate sample size, N ≈ 97 adults.