Concept explainers
For Exercises 7 through 23, perform each of the following steps.
a. State the hypotheses and identify the claim.
b. Find the critical value(s).
c. Find the test value.
d. Make the decision.
e. Summarize the results.
Use the traditional method of hypothesis testing unless otherwise specified.
23. Water Consumption The Old Farmer’s Almanac stated that the average consumption of water per person per day was 123 gallons. To test the hypothesis that this figure may no longer be true, a researcher randomly selected 16 people and found that they used on average 119 gallons per day and s = 5.3. At α = 0.05, is there enough evidence to say that the Old Farmer’s Almanac figure might no longer be correct? Use the P-value method.
Want to see the full answer?
Check out a sample textbook solutionChapter 8 Solutions
Elementary Statistics: A Step By Step Approach
- Follow the steps in testing hypothesis to answer the problem:arrow_forwardA researcher believes that the average amount of calories consumed daily differs between adult males and adult females between the ages of 25 and 35. Suppose she collected data to test her belief and found a p-value of 0.023. Fill in the information for her hypothesis test below. Type of test a. Left-tail b. Right-tail c. Two-tailarrow_forwardDANDANG DOLO... Directions: Read and analyze the given problems below. One of the data/ concepts/values is incorrect. Find the error, then write the correct version. Write your answers on the blanks provided. 1. One thousand five hundred (1,500) randomly selected pine trees were tested for traces of the Bark Beetle infestation. It was found that 153 of them showed such traces. Test the hypothesis that more than 10% of the pine trees have been infested. (Use 5% level of significance.) α = 0.5 Ho= 0.10 Ha: p > 0.10 ERROR: CORRECTED: 2. A sample of 100 students were randomly selected from Pinagpala High School and 18 of them said they are left-handed. Test the hypothesis that less than 20% of the students are left-handed by using a = 0.05 as the level of significance. Ho: p = 0.20 Ha: p = 0.20. α = 0.5 ERROR: It is a one-directional or left-tailed test. CORRECTED: 3. Newborn babies are more likely to be boys than girls. A random sample found 13,173 boys were born among 25,468 newborn…arrow_forward
- A standardized test has a scale that ranges from 3 to 45. A new type of review course for the test was developed by a training company. The accompanying table shows the scores for nine students before and after taking the review course. Complete parts (a) through (d) below. E Click the icon to view the data table. a. Perform a hypothesis test using a= 0.05 to determine if the average test score is higher for the students after the review course when compared with before the course. Let p, be the population mean of matched-pair differences for the score before the course minus the score after the course. State the null and alternative hypotheses. Choose the correct answer below. O A. Ho: Ha = 0 H,: Ha #0 O B. Ho: Ha 20 H,: Hg 0 H,: Ha s0 O D. Ho: Ha s0 H,: Hg>0 OF. Ho: Ha <0 H,: Hg 20 Test Scores O E. Ho: Ha #0 H,: H = 0 Student Before After 26 28 b. Calculate the appropriate test statistic and interpret the results of the hypothesis test using a = 0.05. 23 25 18 16 The test statistic…arrow_forwardAnswer the following problems. Apply the different steps in hypothesis testing. 1. AVS Company has been selling to retail customers in the Pasig City area. They advertise extensively on radio, print ads, and in the internet. The owner would like to review the relationship between the amount spent on advertising expense (in P000s) and sales (in P000s). Below is information on advertising expense and sales for the last 9 months. Month Jan Advertising Expense 10 Sales Revenue Feb Mar Apr May June July Aug Sept 14 9 13 15 8 13 16 12 190 220 235 208 215 175 250 180 170 Find the coefficient of correlation. Determine at the 0.10 significance level whether the correlation in the population is greater than zero.arrow_forwardA. Instructions: Formulate the appropriate null and alternative hypotheses for each situation. A parents' organization in a school is concerned about the proportion of fat content of the burgers sold in the school canteen. This canteen claims that the proportion is only about 18%. But some students believe that the fat content is higher 1. than that. 2. A maternity hospital claims that the mean birth weight of babies delivered in their charity ward is 2.5 kg. But that is not what a group of obstetricians believe.arrow_forward
- When performing a hypothesis test upon two dependent samples, the variable of interest is Group of answer choices a.the absolute value of the differences that exist between the matched-pair data. b.the differences that exist between the matched-pair data. c.the data that is the same in both samples. d.all of the combined data.arrow_forwardSolve the following problems. Use the steps in conducting hypothesis tests.We are interested in whether the proportions of female suicide victims for ages 15 to 24 are the same for the whites and the blacks races in the United States. We randomly pick one year, 1992, to compare the races. The number of suicides estimated in the United States in 1992 for white females is 4,930. Five hundred eighty were aged 15 to 24. The estimate for black females is 330. Forty were aged 15 to 24. We will let female suicide victims be our population.arrow_forwardUse the traditional method in testing the hypothesis in the problems below. In each problem, state the following:a. State the hypotheses and identify the claim.b. Find the critical value(s)c. Find the test valued. Make the decisione. Summarize the result1. Based on previous research and sound theoretical considerations, a cognitive psychologist believes that memory for pictures are superior to memory for words. To test this hypothesis, the psychologist performs an experiment in which students from an introductory psychology class are used as subjects. Eight randomly selected students view 30 slides with nouns printed on them, and another group of eight randomly selected students’ views 30 slides with pictures of the same nouns. Each slide contains either one noun or one picture and is viewed for 4 seconds. After viewing the slides, subjects are given a recall test, and the number of correctly remembered items is measured. The data follow: Use ∝= 0.05. No. of Pictures Recalled 18 21 14…arrow_forward
- Directions: Follow the steps in testing the hypothesis to answer the following problems. a. Identify the given in the problem. b. State the null and alternative hypotheses. c. Determine the test statistic, then compute its value. d. Find the critical value and draw the critical region. e. Draw a conclusion A teacher believes that less than 20% of the students like Mathematics. If 13 out of the 60 randomly selected students like mathematics, is the teachers' claim valid? Use 90% confidence level.arrow_forwardTeacher of a class wants to study the reasons for students' absence. What is needed for her to study? a. Organize the data and analyze it b. Collect the data on the students' absence c. Investigate the reasons and draw conclusion d. All the abovearrow_forwardState the null and alternate hypotheses. Interpret the findings and state your conclusions.arrow_forward
- Holt Mcdougal Larson Pre-algebra: Student Edition...AlgebraISBN:9780547587776Author:HOLT MCDOUGALPublisher:HOLT MCDOUGALGlencoe Algebra 1, Student Edition, 9780079039897...AlgebraISBN:9780079039897Author:CarterPublisher:McGraw HillBig Ideas Math A Bridge To Success Algebra 1: Stu...AlgebraISBN:9781680331141Author:HOUGHTON MIFFLIN HARCOURTPublisher:Houghton Mifflin Harcourt