Mathematics, 20.12.2019 03:31 sam9350

Astockbroker at critical securities reported that the mean rate of return on a sample of 10 oil stocks was 12.6% with a standard deviation of 3.9%. the mean rate of return on a sample of 8 utility stocks was 10.9% with a standard deviation of 3.5%. at the 0.05 significance level, can we conclude that there is more variation in the oil stocks?

Answers: 1

Show answers

Answers

Answer from: bharadwajp9943

H0: $\sigma^2_1 \leq \sigma^2_2$

H1: $\sigma^2_1 \sigma^2_2$

$F=\frac{s^2_1}{s^2_2}=\frac{3.9^2}{3.5^2}=1.242$

$p_v =P(F_{9,7}1.242)=0.396$

Since the $p_v \alpha$ we have enough evidence to FAIL to reject the null hypothesis. And we can say that we don't have enough evidence to conclude that the variation for the oil stocks it's greater than the variation for the utility stocks at 5% of significance.

Step-by-step explanation:

Data given and notation

n_1 = 10 represent the sampe size for the oil stocks

n_2 =8 represent the sample size for the utility stocks

$\bar X_1 =12.6$ represent the sample mean for the oil stocks

$\bar X_2 =10.9$ represent the sample mean for the utility stocks

s_1 = 3.9 represent the sample deviation for the oil stocks

s^2_1 = 15.21 represent the sample variance for the oil stocks

s_2 = 3.5 represent the sample deviation for the utility stocks

s^2_2 = 12.25 represent the sample variance for the utility stocks

$\alpha=0.05$ represent the significance level provided

Confidence =0.95 or 95%

F test is a statistical test that uses a F Statistic to compare two population variances, with the sample deviations s1 and s2. The F statistic is always positive number since the variance it's always higher than 0. The statistic is given by:

$F=\frac{s^2_1}{s^2_2}$

Solution to the problem

System of hypothesis

We want to test if the variation for oil stocks it's higher than the variation for utility stocks, so the system of hypothesis are:

H0: $\sigma^2_1 \leq \sigma^2_2$

H1: $\sigma^2_1 \sigma^2_2$

Calculate the statistic

Now we can calculate the statistic like this:

$F=\frac{s^2_1}{s^2_2}=\frac{3.9^2}{3.5^2}=1.242$

Now we can calculate the p value but first we need to calculate the degrees of freedom for the statistic. For the numerator we have n_1 -1 =10-1=9 and for the denominator we have n_2 -1 =8-1=7 and the F statistic have 9 degrees of freedom for the numerator and 7 for the denominator. And the P value is given by:

P value

$p_v =P(F_{9,7}1.242)=0.396$

And we can use the following excel code to find the p value:"=1-F.DIST(1.242;9;7;TRUE)"

Conclusion

Answer from: Quest

200 miles.45 x 3 (charge per day times days)135$205$ - 135$ = 70$0.35x = 70divide both sides by 0.35200

Answer from: Quest

point a is the center of the circle that passes through points e, f, and g and the center of the circle that passes through points x, y, and z.

Another question on Mathematics

Mathematics, 21.06.2019 12:30

For the following sequence determine the common difference (if it is an arithmetic sequence) or the common ratio (if it is a geometric sequence).

Answers: 3

Answer

Mathematics, 21.06.2019 18:40

2people are trying different phones to see which one has the better talk time. chatlong has an average of 18 hours with a standard deviation of 2 hours and talk-a-lot has an average of 20 hours with a standard deviation of 3. the two people who tested their phones both got 20 hours of use on their phones. for the z-scores i got 1 for the chatlong company and 0 for talk-a-lot. what is the percentile for each z-score?

Answers: 1

Answer

Mathematics, 21.06.2019 19:00

For what value of (y) is 3^3/3^y =1/9

Answers: 1

Answer

Mathematics, 21.06.2019 20:00

Afrequency table of grades has five classes (a, b, c, d, f) with frequencies of 3, 13, 14, 5, and 3 respectively. using percentages, what are the relative frequencies of the five classes?

Answers: 3

Answer

You know the right answer?

Astockbroker at critical securities reported that the mean rate of return on a sample of 10 oil stoc...

Questions

Mathematics, 11.05.2021 22:10

PLEASE PLEASE HELP YA'LL 3RD TIME POSTING AND REALLY NEED HELP What are the resulting coordinates of triangle X′Y′Z′ after rotating triangle XYZ coun...