Tell whether the ordered pair (−1, 4) is a solution of the system. -2x-3y=-10 -3x+y=7
1 answer:
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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.
Answer:
Using trigonometric ratio:
From the given statement:
and sin < 0
⇒ lies in the 3rd quadrant.
then;
Using trigonometry identities:
Substitute the given values we have;
Since, sin < 0
⇒
now, find :
Substitute the given values we have;
Therefore, the exact value of:
(a)
(b)