Answer:
Yes, we can conclude that the population standard deviation of TV watching times for teenagers is less than 2.66
Step-by-step explanation:
H0 : σ² = 2.66²
H1 : σ² < 2.66²
X²c = (n - 1)*s² ÷ σ²
sample size, n = 40
Sample standard deviation, s = 1.9
X²c = ((40 - 1) * 1.9²) ÷ 2.66²
X²c = 140.79 ÷ 7.0756
X²c = 19.897
Using a confidence level of 95%
Degree of freedom, df = n - 1 ; df = 40 - 1 = 39
The critical value using the chi distribution table is 25.6954
Comparing the test statistic with the critical value :
19.897 < 25.6954
Test statistic < Critical value ; Reject the Null
Hence, we can conclude that the population standard deviation of TV watching times for teenagers is less than 2.66
Answer:
153.94 cm²
Step-by-step explanation:
Area of circle = πr² = π(7)² = 49π = 153.94 cm²
Answer:
What's the question for the options?
Answer:
35°
Step-by-step explanation:
Angles on a straight line add up to 180, so 180-145 is equal to
Area of a circle = pir^2
The radius is half the diameter so is 2 metres
So r^2 is 4
So the answer is 4pi or 12.57 metres squared
Let me know if you have any questions