Which of the following is a statistical question?
1 answer:
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Answer:
a) the sample size is 400
b) 95% confidence Interval for p is ( 0.0286, 0.0714 )
Step-by-step explanation:
Given the data in the question;
sample size n = 400
x = 20
p = x / n = 20 / 400 = 0.05
q = 1 - p = 1 - 0.05 = 0.95
a)
n = 400
Hence, the sample size is 400
b) 95% confidence Interval for p;
At 95% confidence interval,
significance level ∝ = 1 - 95% = 1 - 0.95 = 0.05
∝/2 = 0.05 / 2 = 0.025
so, Z critical Value ; = 1.96 { from table }
So for Confidence Interval for p;
⇒ p' ± √( p'q' / n )
we substitute
⇒ 0.05 ± 1.96√( (0.05 × 0.95 ) / 400 )
⇒ 0.05 ± 1.96√( 0.00011875 )
⇒ 0.05 ± 1.96 × 0.010897
⇒ 0.05 ± 0.021358
⇒ ( 0.05 - 0.021358 ), ( 0.05 + 0.021358 )
⇒ ( 0.0286, 0.0714 )
Therefore, 95% confidence Interval for p is ( 0.0286, 0.0714 )
Answer:
Emma spend 8 hours in homework in a week and Jared spends 16 hours in homework in 2 weeks.
Step-by-step explanation:
Two quantities P and Q are said to be in PROPORTION if and only if for all values of P and q, we get:
Here, k : PROPORTIONALITY CONSTANT
Case: 1
5 hour piano practice in 1 week.
So, the piano practice in 2 weeks( 1 x 2) = 2 x 5 = 10 hours
But here, it is given to be 12 hours in 2 weeks.
Hence, NOT PROPORTIONAL.
Case 2:
70 words in 60 seconds.
So, the words typed in 210 seconds ( 60 x 3.5) = 70 x 3.5 = 240 words
But here, it is given to be 280 words in 210 seconds.
Hence, NOT PROPORTIONAL.
Case: 3
8 hour homework in 1 week.
So, the homework done in 2 weeks( 1 x 2) = 2 x 8 = 16 hours
It is given to be 16 hours in 2 weeks.
Hence, PROPORTIONAL.
Case: 4
15 miles in 78 minutes.
So, the distance covered in 102 minutes (78 x 1.3) = 15 x 1.3 = 19.6 miles
But here, it is given to be 17 miles in 102 minutes.
Hence, NOT PROPORTIONAL.
Case: 5
18 miles in 45 minutes.
So, the distance covered in 55 minutes (45 x 1.2) = 18 x 1.2 = 21.6 miles
But here, it is given to be 22 miles in 55 minutes.
Hence, NOT PROPORTIONAL.
Hence, the only proportional case is Emma spend 8 hours in homework in a week and Jared spends 16 hours in homework in 2 weeks.