Answer:
t= 0.4933
t ≥ t ( 0.025 ,8 ) = 2.306
Since the calculated value of t= 0.4933 is less than t ( 0.025 ,8 ) = 2.306 therefore we accept the null hypothesis at 5 % significance level . On the basis of this we conclude that the book had no effect on their scores.
Step-by-step explanation:
We state our null and alternative hypotheses as
H0: ud= 0 Ha: ud≠0
The significance level is set at ∝= 0.05
The test statistic under H0 is
t= d`/ sd/√n
which has t distribution with n-1 degrees of freedom
The critical region is t ≥ t ( 0.025 ,8 ) = 2.306
Computations
Student Scores before Scores after Difference d²
reading book ( after minus before)
1 720 740 20 400
2 860 860 0 0
3 850 840 -10 100
4 880 920 40 1600
5 860 890 30 900
6 710 720 10 100
7 850 840 -10 100
8 1200 1240 40 1600
<u>9 950 970 20 40</u>
<u>∑ 6930 8020 140 4840</u>
d`= ∑d/n= 140/9= 15.566
sd²= 1/8( 4840- 140²/9) = 1/8 (4840 - 2177.778) = 2662.22/8= 332.775
sd= 18.2422
t= 3/ 18.2422/ √9
t= 0.4933
Since the calculated value of t= 0.4933 is less than t ( 0.025 ,8 ) = 2.306 therefore we accept the null hypothesis at 5 % significance level . On the basis of this we conclude that the book had no effect on their scores.
Aren’t you supposed to multiply the exponents to where it’s 5^24 ?
Um..... probably 500 cause 200 less is 300 and 200 more is 700
Answer:
It will take 15 years for $500 to yield $900 at an interest rate of 0.12
Step-by-step explanation:
Simple Interest equals Principal times Rate times The time in years,
That is SI = P*R*T
SI is $900
P = $500
R = 0.12
T i.e. Time is unknown
T will be equal to SI divided by P*R
i.e., T = SI/PR
T = $900/$500*0.12 = 900/60
T = 15 years.
Therefore, it will take $500 investment to yield $900 interest in 15 years at an interest rate of 0.12
Answer:
1 in 144
Step-by-step explanation:
There is one 8 on a 12-sided die, so the probability of rolling an 8 once is 
.
We are rolling twice, so 
.
