A researcher claims that the mean weight of the population of dudes at CSUSB is 250 lbs (dudes love their tacos). A sample of dudes found the following: n = 47 avg = 232 S = 10 HO: mu = 250; Ha: mu != 232 z = -12.34, reject null hypothesis z = 12.34, reject null hypothesis z = -12.34, do not reject null hypothesis z =12345, do not reject null hypothesis Ot= 12.34, do not reject null hypothesis

If random samples, each with n = 16 scores, are selected from a normal population with µ = 100 and σ = 20, how much difference, on average, should there be between a sample mean and the population mean?

An engineer is comparing voltages for two types of batteries (K and Q) using a sample of 35 type K batteries and a sample of 44 type Q batteries. The type K batteries have a mean voltage of 8.56, and the population standard deviation is known to be 0.565. The type Q batteries have a mean voltage of 8.74, and the population standard deviation is known to be 0.307. Conduct a hypothesis test for the conjecture that the mean voltage for these two types of batteries is different. Let µj be the true mean voltage for type K batteries and µ2 be the true mean voltage for type Q batteries. Use a 0.05 level of significance. Step 3 of 4: Determine the decision rule for rejecting the null hypothesis Ho. Round the numerical portion of your answer to two decimal places.

A sample of marine iguanas (n=30) from the Galapagos Islands has an average length of 2.8ft with a sample variance of 0.43ft. What is the 95% confidence interval of this sample?

is a simple random sample. 1) Ten students in a graduate program were randomly selected. Their grade point averages (GPAs) when they entering entered the program were between 3.5 and 4.0. The following data were obtained regarding their GPAs on program versus their current GPAs. the Entering GPA 3.5 3.8 3.6 3.6 3.5 3.9 4.0 3.9 3.5 3.7 Current GPA 3.6 3.7 3.9 3.6 3.9 3.8 3.7 3.9 3.8 4.0

A study found that a 95% confidence interval for the mean μ of a particular population was computed from a random sample of 1200 people and found it to be 10 ± 4. Therefore, we may conclude:

Cindy is a server at a local restaurant who makes, on average, $58 in tips per daytime shift. Cindy thinks she will make more if she moves to the nighttime shift. Her manager will choose five random nighttime shifts for Cindy to work. Cindy plans to conduct a significance test on the hypotheses H0: mu = 58; Ha: mu > 58 at the alpha = 0.05 level, where  is the true mean amount of tips Cindy will make working nighttime shifts. Are the conditions for performing the test met? No, the 10% condition is not met. No, the sample size is too small, and a Normal distribution cannot be assumed. Yes, all conditions are met for performing a significance test about the mean. Yes, only the random condition must be met in order to perform a significance test. No, there is no way the manager could choose a random sample of shifts to work.

a sample of employees is selected and it is found that 45% own a computer which is it a statistic or a parameter

The producers of a new toothpaste claim that it prevents more cavities than other brands of toothpaste. A random sample of 60 people used the new toothpaste for 6 months. The mean number of cavities at their next checkup is 1.5. In the general population, the mean number of cavities at a 6-month checkup is 1.73 (σ= 1.12) . Is this a one-or two-tailed test? What are H0 and Ha for this study?

A random sample of n₁ = 217 people who live in a city were selected and 106 identified as a "dog person." A random sample of n₂ = 114 people who live in a rural area were selected and 66 identified as a "dog person." Find the 90% confidence interval for the difference in the proportion of people that live in a city who identify as a "dog person" and the proportion of people that live in a rural area who identify as a "dog person." Round answers to to 4 decimal places. < P1 P2 <