Question

An instructor whishes to see whether the variation in scores of the 23 students in her class is less than the variance of the population. The variance of the class is 198. Is there enough evidence to support the claim that the variation of the students is less than the population variance (�� 2 = 225) at α = 0.05?. Assume that the scores are normally distributed

142

likes
710 views

Answer to a math question An instructor whishes to see whether the variation in scores of the 23 students in her class is less than the variance of the population. The variance of the class is 198. Is there enough evidence to support the claim that the variation of the students is less than the population variance (�� 2 = 225) at α = 0.05?. Assume that the scores are normally distributed

Expert avatar
Santino
4.5
100 Answers
1. State the null and alternative hypotheses:
H_0: \sigma^2 = 225
H_a: \sigma^2 < 225

2. Identify sample size, sample variance, population variance, and significance level:
n = 23
s^2 = 198
\sigma_0^2 = 225
\alpha = 0.05

3. Calculate the Chi-Square test statistic:
\chi^2 = \frac{(23-1)s^2}{\sigma_0^2} = \frac{22 \cdot 198}{225} \approx 19.36

4. Determine the critical value from the Chi-Square distribution table:
\chi^2_{0.05, 22} \approx 12.338

5. Compare the test statistic to the critical value:
19.36 > 12.338

6. Make a decision:
\text{Do not reject } H_0

Answer:
\text{There is not enough evidence to support the claim that the variation of the students is less than the population variance at } \alpha = 0.05

Frequently asked questions (FAQs)
What is the value of x if the sum of its square and twice its absolute value is equal to 15?
+
What is the time required for a car to travel 100 km at a speed of 80 km/h?
+
What is the value of f(x) if f(x) = c, where c is a constant function?
+
New questions in Mathematics
12-6x=4x+2
90 divided by 40
What will be the density of a fluid whose volume is 130 cubic meters contains 16 technical units of mass? If required Consider g=10 m/s2
The data set (75, 85, 58, 72, 70, 75) is a random sample from the normal distribution No(µ, σ). Determine a 95% two-sided confidence interval for the mean µ .
-0.15/32.6
A regional candy factory sells a guava roll at a price of $48, the monthly fixed costs amount to $125,000 and the variable cost for making a guava roll is $28. Determine: a) The equation of the total income from the production of guava rolls.
how many arrangement can be made of 4 letters chosen from the 8 letters of the world ABBSOLUTE
A person borrows rm 1000 from a bank at an interest rate of 10%. After some time, he pays the bank rm 1900 as full and final settlement of the loan. Estimate the duration of his loan.
There were no defectives in a sample of 1 light bulb does this sample provide sufficient evidence that in the warehouse with millions of light bulbs fewer than 10% are defective?
What’s the slope of a tangent line at x=1 for f(x)=x2. We can find the slopes of a sequence of secant lines that get closer and closer to the tangent line. What we are working towards is the process of finding a “limit” which is a foundational topic of calculus.
The simple average of 15 , 30 , 40 , and 45 is
7.57 Online communication. A study suggests that the average college student spends 10 hours per week communicating with others online. You believe that this is an underestimate and decide to collect your own sample for a hypothesis test. You randomly sample 60 students from your dorm and find that on average they spent 13.5 hours a week communicating with others online. A friend of yours, who offers to help you with the hypothesis test, comes up with the following set of hypotheses. Indicate any errors you see. H0 :x ̄<10hours HA : x ̄ > 13.5 hours
Sections of steel tube having an inside diameter of 9 inches, are filled with concrete to support the main floor girder in a building. If these posts are 12 feet long and there are 18 of them, how many cubic yards of concrete are required for the job?
List the remaining zeros of the polynomial with the given zeros Zeros are: 2, 3i, and 3 + i
36 cars of the same model that were sold in a dealership, and the number of days that each one remained in the dealership yard before being sold is determined. The sample average is 9.75 days, with a sample standard deviation of 2, 39 days. Construct a 95% confidence interval for the population mean number of days that a car remains on the dealership's forecourt
factor the polynomial completely over the set of complex numbers b(x)=x^4-2x^3-17x^2+4x+30
Read the “Local Communities as Stakeholders: Does Amazon Really Need Tax Breaks?” example on p. 83 in Ch. 3 of Management: A Practical Introduction. In your response, discuss whether you feel that tax breaks for big companies benefit local communities. Describe ways to attract business to a region without having a negative impact on the larger community.
A candy manufacturer must monitor deviations in the amount of sugar in their products They want their products to meet standards. They selected a random sample of 20 candies and found that the sandard deviation of that sample is 1.7. What is the probabilty of finding a sample variance as high or higher if the population variance is actually 3277 Assume the population distribution is normal.
7-1=6 6x2=12 Explain that
A grain silo has a height of 8.8m with a 11.4m diameter. If it is filled 0.5% of it's volume, how much grain (m^3) is stored in the silo? (0 decimal places)