Tutors Answer Your Questions about Hypothesis-testing (FREE)
Question 1129386: suppose that in a random selection of
100
100 colored candies,
27
27% of them are blue. The candy company claims that the percentage of blue candies is equal to
29
29%. Use a
0.05
0.05 significance level to test that claim.
Click here to see answer by Boreal(15235)   |
Question 1129582: A random sample of
861
861 births included
430
430 boys. Use a
0.10
0.10 significance level to test the claim that
50.5
50.5% of newborn babies are boys. Do the results support the belief that
50.5
50.5% of newborn babies are boys?
Click here to see answer by Boreal(15235) |
Question 1129604: In a program designed to help patients stop smoking,
195
195 patients were given sustained care, and
83.6
83.6% of them were no longer smoking after one month. Use a
0.01
0.01 significance level to test the claim that
80
80% of patients stop smoking when given sustained care.
Click here to see answer by Boreal(15235) |
Question 1129601: An online poll asked: "Do you believe the Loch Ness monster exists?" Among
21 comma 346
21,346 responses,
69
69% were "yes." Use a
0.05
0.05 significance level to test the claim that most people believe that the Loch Ness monster exists. How is the conclusion affected by the fact that Internet users who saw the question could decide whether to respond?
Click here to see answer by Boreal(15235) |
Question 1129971: A local university claims that if you enroll in their university you will have your degree completed within 4.5 years. To test this a sample of 81 graduates was taken. The sample yielded an average of 4.75 years with a standard deviation of 1.2 years.
a. Set up the Hypothesis to test this University’s Claim at a level of significance of .05. (α=.05)
b. What is the Test Statistic and Critical Value for the above problem?
What is the P-value for the above problem?
c. Would you reject the Null Hypothesis based on information obtained in part b.
Click here to see answer by Boreal(15235) |
Question 1129889: The claim is that for a smartphone carrier's data speeds at airports, the mean is
mu
μ
equals
=
18.00
18.00 Mbps. The sample size is n
equals
=
15
15 and the test statistic is t
equals
=
negative 2.212
−2.212
Click here to see answer by Boreal(15235) |
Question 1131519: In a study of court administration the following times to disposition were found in 20 randomly
selected cases of a certain type. Test the hypotheses that the average time to disposition is 80 days or
less; use the 1% significance level. Assume disposition time, x, is normally distributed.
Click here to see answer by Boreal(15235) |
Question 1140862: It is recommended that an adult get 8 hours of sleep every night. To test whether mothers of newborn babies get enough sleep, the national sleep foundation conducted a random survey of 151 mothers of newborn babies and found that their mean sleep time was 7.8 hours with a standard deviation of 1.4 hours. Does the evidence suggest that mothers of newborn babies get less than the recommended hours of sleep? conduct a hypothesis test at a=0.05 to test the claim. Show all 4steps of hypothesis test clearly.
Thanks!
Click here to see answer by Boreal(15235) |
Question 1140863: In a recent survey conducted by the Gallup poll, 28% of Males and 36% of Females believe that "Obesity impacts individuals". A statistician used this survey and found that a 95% CI estimating the difference in percentage of males and females who believe Obesity impacts individuals is (-13%, -2%). Based on this interval, can you conclude that there is a difference in the percentage of males and females who believe obesity impacts individuals? Justify.
Click here to see answer by Boreal(15235) |
Question 1150920: The following information is available.
Ho: m < 10
H1: m > 10
The sample mean is 12 for a sample of 36. The population follows the normal distribution and the standard deviation is 3. Use the .02 significance level.
(a) Is this a one- or two-tailed test?
(b) What is the decision rule?
(c) What is the value of the test statistic?
(d) What is your decision regarding Ho?
(e) What is the p-value? Interpret it.
Click here to see answer by jim_thompson5910(35256) |
Question 1150934: A nationwide sample of influential Republicans and Democrats was asked as a part of a comprehensive survey whether they favored lowering environmental standards so that high-sulfur coal could be burned in coal-fired power plants. The results were:
Number sampled : 1,000 (republican) , 800 (democrats)
Number in favor: 200 (republican) , 168 (democrats)
At the .02 level of significance, can we conclude that there is a larger proportion of Democrats in favor of lowering the standards?
Click here to see answer by jim_thompson5910(35256) |
Question 1161943: It has been found that the average time
Internet users spend online per week is 18.3 hours. A
random sample of 48 teenagers indicated that their
mean amount of Internet time per week was 20.9 hours
with a population variance of 32.49. At the 0.02 level of
significance, can it be concluded that the mean time
differs from 18.3 hours per week?
a. State the hypotheses and identify the claim.
b. Find the critical value(s).
c. Compute the test value.
d. Make the decision.
e. Summarize the results.
Click here to see answer by Boreal(15235) |
Question 1162409: In BUBT, business faculty’s students were randomly assigned to one of two Math teachers - Mr. X and Mrs. Y. After the assignment, Mr. X had 30 students, and Mrs. Y had 25
students. At the end of the semester, each class took the same standardized test. Mr. X's
students had an average test score of 78, with a standard deviation of 10; and Mrs. Y's
students had an average test score of 85, with a standard deviation of 15.
Click here to see answer by ikleyn(52781)  |
Question 1171312: A female patient has had her red blood cell count tested on 6 occasions. A mean of 4.4
with sample standard deviation, s, of 0.28 was found. Generally, healthy, female adults
have a red blood cell count of 4.8. Conduct a hypothesis test to determine if the red
blood cell count for this patient is lower than normal. (Use a = 0.05.)
Click here to see answer by math_tutor2020(3817) |
Question 1172794: A study of sample of 196 bank accounts showed the average size of bank accounts is Rs. 7542. From the previous studies of bank accounts, it is known that the standard deviation is Rs. 2984. Test the hypothesis that μ = Rs. 8000 against the hypothesis μ ≠8000. Use a 1% level of significance.
Click here to see answer by Boreal(15235) |
Question 1174740: Please help me solve this, thank you!
A random sample of 20 cans of milk showed an average weight of
198.5 grams with a standard deviation of 15 grams. Is this in line with
the manufacturer’s claim of an average weight of 200 grams, using a
0.05 level of significance?
Click here to see answer by ewatrrr(24785)  |
Question 1174738: Please help me solve this:
A certain brand of alcohol claims that the alcohol concentration of
the product is 70%. To test this claim, a random sample of 15
bottles of this brand were tested and an average of 68% alcohol
concentration was obtained with a standard deviation of 8%. Is the
claim valid at the 0.05 level of significance?
Click here to see answer by ewatrrr(24785) |
Question 1174739: Please help me solve this:
It has been known in the past that the average number of children of
a Filipino family is 6. A random sample of 25 families were selected and
found to have an average of 3 children with a standard deviation of 1
child. Can we say that the number of children of a Filipino family has
gone lower?
Thank you!
Click here to see answer by Theo(13342)  |
Question 1174776: PLEASE HELP ME SOLVE THIS, THANK YOU!
A certain brand of alcohol claims that the alcohol concentration of
the product is 70%. To test this claim, a random sample of 15
bottles of this brand were tested and an average of 68% alcohol
concentration was obtained with a standard deviation of 8%. Is the
claim valid at the 0.05 level of significance?
Click here to see answer by ewatrrr(24785) |
Question 1175558: The probability that a passenger’s bag will be mishandled on a U.S. airline is .0046. During spring break, suppose that 500 students fly from Minnesota to various southern destinations.
(a) What is the expected number of mishandled bags? [2]
(b) What is the approximate probability of no mishandled bags? What is the probability of more than two mishandled bags? [4]
(c) Would you expect the approximation to be accurate (cite a rule of thumb)?
Click here to see answer by Boreal(15235) |
Question 1175558: The probability that a passenger’s bag will be mishandled on a U.S. airline is .0046. During spring break, suppose that 500 students fly from Minnesota to various southern destinations.
(a) What is the expected number of mishandled bags? [2]
(b) What is the approximate probability of no mishandled bags? What is the probability of more than two mishandled bags? [4]
(c) Would you expect the approximation to be accurate (cite a rule of thumb)?
Click here to see answer by ewatrrr(24785) |
Question 1175557: For the following hypothesis test:
H0: μ ≤ 70
HA: ÎĽ > 70
with n = 20, x = 71.2, s = 6.9, and a = 0.1, state
a. the decision rule in terms of the critical value of the test statistic [2]
b. the calculated value of the test statistic [2]
c. the conclusion [1]
Click here to see answer by Boreal(15235) |
Question 1175556: A sample of 200 customers at a supermarket showed that 28 used a debit card to pay for their purchases.
(a) Find the 95 percent confidence interval for the population proportion. [2]
(b) Why is it OK to assume normality in this case? [2]
(c) What sample size would be needed to estimate the population proportion with 90 percent confidence and an error of +/- 0.03? [2
Click here to see answer by ewatrrr(24785) |
Question 1175553: Which statement is incorrect? Explain.
a. If p = 0.50 and n = 100, the estimated standard error of the sample proportion is 0.05. [2]
b. In a sample size calculation for estimating π, it is conservative to assume π = 0.50. [2]
c. If n = 250 and p = 0.07 it is not safe to assume normality in a confidence interval for π. [2]
Click here to see answer by Boreal(15235) |
Question 1178927: The average score of all pro golfers for a particular course has a mean of 70 and a standard deviation of 3.0. Suppose 36 golfers played the course today. Find the sum of two values of scores that contain 95% of the sample scores equidistant from mean.
Click here to see answer by ewatrrr(24785) |
Question 1181433: Assuming that the population standard deviation is unknown for a
randomly selected sample whose size is 11, sketch the rejection region
for a one-tailed test with 99% confidence. Does t = 2.86 fall in the
rejection region?
Click here to see answer by Theo(13342) |
Question 1181945: A local government official claims that only up to 25% of all public school students in the city own an electronic gadget that can be used for distance learning like a cellphone, tablet, or laptop. To test the claim, a group of Grade 11 Statistics students made a survey and found out that out of 1,000 randomly selected students, 275 indicated that they are ready for Online learning. Can we infer from the data that the local official is true to his claim? Set up the Rejection Region and the Critical Values for Left-Tailed, Right-Tailed, and Two-Tailed tests. Use É‘=.01
Click here to see answer by Boreal(15235) |
Question 1182426: Give complete computation/solutions and 6 steps in solving.
1.A firm that manufactures tires would like to determine whether the machine that produces these tires is still in good condition. The average diameter of these tires should be 36 inches to fit most of the car models. To check the machine, a sample of 100 tires were measures and showed a mean diameter of 36.8 inches with standard deviation of 1.83 inch. Should the manufacturer change the machine? Use a 10% level of significance.
2. A cigarette manufacturer claims that the average nicotine content of their cigarette does not exceed by 3.4 mg. A random sample of 15 cigarettes was taken and found to have average nicotine content of 4.5 mg with SD of 1.5 mg. Are you going to accept the manufacturer’s claim at 0.01 level of significance?
3. A manufacturer packs sugar into plastic bags . Each bag is to hold 5 kgs whenever the production is under control. At one period, a sample of 17 bags was taken to check the process and was to found to weigh 5.6 kgs with SD of 0.75 kgs. Is the manufacturing process under control? Use 𝛼=0.01.
Thanks in advance!
Click here to see answer by ikleyn(52781) |
Question 1182428: 2. A cigarette manufacturer claims that the average nicotine content of their cigarette does not exceed by 3.4 mg. A random sample of 15 cigarettes was taken and found to have average nicotine content of 4.5 mg with SD of 1.5 mg. Are you going to accept the manufacturer’s claim at 0.01 level of significance?
Click here to see answer by Boreal(15235) |
Question 1182469: SHOW THE COMPLETE SOLUTION AND THE SIX STEPS IN SOLVING THIS HYPOTHESIS TESTING
The mean number of close friends for the population of people living in the U.S. is 5.7. The standard deviation of scores in this population is 1.3. An investigator predicts that the mean number of close friends for introverts will be significantly different from the mean of the population. The mean number of close friends for a sample of 36 introverts is 6.5. Do these data support the investigator's prediction? Use an alpha level of .05.
Thank you very much in advance!
Click here to see answer by Theo(13342) |
Question 1181946: The ABM Coffee Company claims that 20% of the coffee drinkers in Pinalagad, Malinta prefer their brand, the Ang Barako Mo coffee. To test the claim, a group of CNHS Grade 11 students conducted a survey, which they found out. Out of the 500 randomly selected residents, 95 indicated that ABM coffee is the reason why they wake up in the morning. Set up the Rejection Region and the Critical Values for Left-Tailed, Right-Tailed, and Two-Tailed tests. Use É‘=.10.
Click here to see answer by Boreal(15235) |
Question 1183752: For each of the following tobs values, determine the highest level of
significance associated with the decision taken.
tobs df Decision
(i) 4.000 17 Reject Ha for a two-tailed test
(ii) 1.200 120 Reject Ha for a one-tailed test
(iii) -2.660 16 Reject Ha for both one-tailed
and two-tailed test
(iv) -1.586 60 Reject Ha for a one-tailed te
Click here to see answer by MathLover1(20849)  |
Question 1183969: It has been determined that 37 out of 100 adult Americans that did not attend college believe in extra-terrestrials. However, from a random sample of 100 adult Americans that did not attend college 43 claim that they believe in extra-terrestrials. Does this indicate that the proportion of people who did not attend college and who believe in extra-terrestrials has changed? Conduct a hypothesis test with a = 0.01 and interpret the results. (10 points)
Click here to see answer by Boreal(15235) |
Question 1187490: The Mathematical Anxiety Rating Scale (MARS) measures an individuals level of mathematical anxiety on a scale from 25 (no anxiety) to 100 (highest anxiety). A group of researcher administered the MARS to 50 students. One of the objectives of the study was to determine if there is a difference between levels of mathematical anxiety experienced by male and female psychology students.
alpha level=0.05level of significance, is there evidence of a difference in the mean mathematical anxiety experienced by male and female psychology students?
Solution:
Step 1: State the hypotheses
Ho:
Ha:
Step 2: The level of significance and the critical region
Step 3: Compute for the value of t test.
Step 4: Decision rule.
Step 5. Conclusion.
Please help me with this problem, this is the only problem that I haven't finished yet 🥺 and the deadline will be this coming Wednesday. Thankyou in advance. GB
Nov. 10 11:59 pm
Click here to see answer by Boreal(15235) |
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