Answer:
A
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
Answer:
1 Original amount: 20
End amount: 15
<h3>(20 - 15)/20 x 100 = (5/20) x 100 = 25% decrease</h3>
2 Original amount: 30
End amount: 45
<h3>
(45 - 30)/30 x 100 = (15/30) x 100 = 50% increase </h3>
3 Original amount: 625
End amount: 550
<h3>
550/625 =550 ÷ 625 =0.88</h3><h3>
0.88 =0.88 × 100/100 =(0.88 × 100)/100 =88/100 =88% decrease</h3>
4 Original amount: 320
End amount: 112
<h3>
(112-320):320x100 =</h3><h3>
100 =(112:320-1)x100 =</h3><h3>
100 =35-100 = -65% decrease</h3>
5 Original amount: 165
End amount: 222.75
<h3>
165/222.75 =165 ÷ 222.75 ≈0.740740740740741</h3><h3>
0.740740740740741 =0.740740740740741 × 100/100 =(0.740740740740741 × 100)/100 ≈74.074074074074/100 =74.074074074074% ≈74.07% Increase </h3>
6 Original amount: 326
End amount: 423.80
<h3>
(423.8-326):326x100 =</h3><h3>
100 =(423.8:326-1)x100 =</h3><h3>
100 =130-100 = 30% Increase </h3>
7 Original amount: 27
End amount: 38.61
<h3>
(38.61-27):27x100 =</h3><h3>
100 =(38.61:27-1)x100 =</h3><h3>
100 =143-100 = 43% Increase</h3>
8 Original amount: 60
End amount: 70.02
<h3>
(70.02-60):60x100 =</h3><h3>
100 =(70.02:60-1)x100 =</h3><h3>
100 =116.7-100 = 16.7% Increase</h3>
Answer:
15
Step-by-step explanation:
Answer:
Omg it really does...
Step-by-step explanation:
