Answer: 18.75 for each girl
Step-by-step explanation:
First you take the unit rate 2.50 multiply by 5.
2.50 x 5 = 12.50
12.50 x 3 = 37.50
37.50 / 2 = 18.75
5(n+6)=48
5n+30=48
5n=18
n=18/5
3x + (x+3) = 19
4x + 3 = 19
4x = 16
x = 4
y= x+3
y= 4+3
y= 7
Answer:
n
Step-by-step explanation:
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
