In an old study, the weight of a certain breed of pig had a standard deviation of 3.8 pounds. What sample size should be used to estimate the mean weight of that breed of pig for a new study? Assume a margin of error of 0.7 pounds and a confidence level of 99% is desired.

You may need to use the appropriate technology to answer this question. Is there any difference in the variability in golf scores for players on a women's professional golf tour and players on a men's professional golf tour? A sample of 20 tournament scores from events in a tour for women showed a standard deviation of 2.4671 strokes, and a sample of 30 tournament scores from events in a tour for men showed a standard deviation of 2.2182. Conduct a hypothesis test for equal population variances to determine if there is any statistically significant difference in the variability of golf scores for male and female professional golfers. Use a = 0.10. State the null and alternative hypotheses. Ho: Find the value of the test statistic. (Round your answer to two decimal places.) Find the p-value. (Round your answer to four decimal places.) p-value = State your conclusion. O Reject Ho. We cannot conclude that there is a difference in the variability of golf scores for male and female…

Steve believes that his wife's cell phone battery does not last as long as his cell phone battery. On eleven different occasions, he measured the length of time his cell phone battery lasted and calculated that the mean was 16.4 hours with a standard deviation of 6.4 hours. He measured the length of time his wife's cell phone battery lasted on seven different occasions and calculated a mean of 23.3 hours with a standard deviation of 4.2 hours. Assume that the population variances are the same. Let Population 1 be the battery life of Steve's cell phone and Population 2 be the battery life of his wife's cell phone. Step 1 of 2: Construct a 90 % confidence interval for the true difference in mean battery life between Steve's cell phone and his wife's. Round the endpoints of the interval to one decimal place, if necessary.

Using traditional methods, it takes 10.4 hours to receive a basic driving license. A new license training method using Computer Aided Instruction (CAI) has been proposed. A researcher used the technique with 23 students and observed that they had a mean of 10.8 hours with a standard deviation of 1.9. A level of significance of 0.1 will be used to determine if the technique performs differently than the traditional method. Assume the population distribution is approximately normal. State the null and alternative hypotheses. E Keypad E Tables Keyboard Shortcuts Answer "H Submit Answer O 2021 Hawkes Learning search 31°F Clear ^ E %96

Two brands of batteries are tested, and their voltages are compared. The summary statistics follow.  For sample 1, the sample size is 27; the population standard deviation is 0.3 volts and the mean is 9.2 volts. For sample 2, the sample size is 30; the population standard deviation is 0.1 volts and the mean is 8.8 volts. Is the mean of sample 1 smaller than the mean of sample 2? Using a significance level of 0.05.   a) Identify the claim and state the hypotheses.    b) What is the test statistics? Find the critical values (s). c) Make the decision to reject or not reject the null hypothesis and explain why. d) Graph your decision and include all the values. That is, the mean, the standard deviation, the critical value(s), the rejection region. e)    Set up the formula with the correct numbers for the 95% confidence interval of the mean number of jobs.

A study is conducted to find the mean life of a certain manufacturer's car batteries. A random sample of 34 batteries is selected and a mean of 47.5 months with a standard deviation of 7.3 months is found. Find a 95% confidence interval for the mean battery life.

In a random sample of 5 mobile​ devices, the mean repair cost was ​$60.00 and the standard deviation was ​$12.00. Assume the population is normally distributed and use a​ t-distribution to find the margin of error and construct a 95​% confidence interval for the population mean. Interpret the results.

Suppose a sample of 30 students are given an IQ test. The sample has a standard deviation of 12.23 points. Assuming IQ test score follow a normal distribution, suppose the researcher wishes to obtain a 90% confidence interval for the population standard deviation.

CNN/Money reports that the mean cost of a speeding ticket, including court fees, was $150.00 in 2002. A local police department claims that this amount has increased. To test their claim, they collect data from a simple random sample of 150 drivers who have been fined for speeding in the last year, and find that they paid a mean of $154.00 per ticket. Assuming that the population standard deviation is $17.54, is there sufficient evidence to support the police department’s claim at the a = 0.05 significance level?

Scores on a standarized exam are known to follow a normal distribution with a standard deviation of 5. A researcher finds a random sample of 25 exam scores has a mean score of 72. Use this to find a 88% confidence interval for the mean exam score of all students taking the exam.