assignment9

Which two fields of the ANOVA summary table help us find the critical value? Select all that apply      A.df between   B.MS within   C.df within   D. MS between

Empirical attention span studies established that college students’ attention span is normally distributed for about 20 ± 2.5 minutes (µ ± σ). However, during Covid-19 pandemic, many studies reported that college students’ attention span has been shorten. To verify this information, a neuropsychologist conducts an experiment to measure the attention span for a sample of college students. The data were recorded as below:   9, 10, 12, 17, 19, 20, 13, 15, 14, 11   What is the probability that we made a Type I error? What would this probability be in terms of the independent and dependent variables? Is there a risk of a Type II error?

Empirical attention span studies established that college students’ attention span is normally distributed for about 20 ± 2.5 minutes (µ ± σ). However, during Covid-19 pandemic, many studies reported that college students’ attention span has been shorten. To verify this information, a neuropsychologist conducts an experiment to measure the attention span for a sample of college students. The data were recorded as below:   9, 10, 12, 17, 19, 20, 13, 15, 14, 11        A- What is the dependent variable? B- What is the level of measurement of the dependent variable? c- Is there a significant difference in attention span between the sample and the general college student population? Test at the alpha = .01 level. D- Compute Cohen’s d

A sample of 20O Allen's Hummingbird's (Selasphorus sasin) found the sample mean weight to be 3.15 grams. It is known that o = 0.33 grams What can we assert with 95% confidence about the maximum error? 0.05 grams 0.07 grams 0.04 grams 0.06 grams

A random sample of n = 100 observations produced a mean of z = 31 with a standard deviation of s = 3. %3D %3D (a) Find a 99% confidence interval for u Lower-bound: Upper-bound: (b) Find a 90% confidence' interval for u Lower-bound: Upper-bound: (c) Find a 95% confidence interval for u Lower-bound: Upper-bound:

uestion 34. After having made a decision on the test at the significance of a = 0.05, the most ppropriate conclusion in the context of research is A) There is not any significant difference between the species with respect to population mean brain eptide content. B) There is a significant difference between the species with respect to population mean brain peptide ontent. C) The population mean brain peptide content of skate fish is significantly greater than that of dogfish. D) The population mean brain peptide content of skate fish is not significantly greater than that of dogfish. E) The population mean brain peptide content of skate fish is exactly the same as that of dogfish. Questions 35-36. The information about head sizes was collected over 18 pilots to determine the feasibility of using cheap cardboard callipers to make the measurements, instead of metal ones which were expensive and uncomfortable. The head size of each pilot was measured once using a cardboard calliper and…

Determine the critical value zα/2zα/2 that corresponds to a 96% level of confidence.

8)a nationwide survey of college students was conducted  and found that students spend 2 hours studying. A professor at your school wnats to determine whether the time students spend at your school is significantly different  from the 2 hours . A random sample of 15 statistic students is carried out and the findings indicate an average of 1.75 hours with a standard deviation of 0.24 hours. Test at the 5% level of significance a) the critical value of t is 1.761. the calculated value of t is -4.03 b)the critical value of t is +-2.145. the calulated value is -4.03 c)the critical value of t is +- 1.761 the calulated value is -1.041 d)the t test should not be used rather use the z test e)the critical value of t is -4.03 the calulated value is +-2.145

A random sample of 12 size AA batteries for toys yield a mean of 2.99 hours with standard deviation, 0.75 hours. (a) Find the critical value, t*, for a 99% CI (give to at least 3 decimal places). t* = (b) Find the margin of error for a 99% CI (give to at least 2 decimal places). %23

An airline company is interested in improving customer satisfaction rate from the 66% currently claimed. The company sponsored a survey of 262 customers and found that 184 customers were satisfied. What is the test statistic z? What is the p-value? Does sufficient evidence exist that the customer satisfaction rate is higher than the claim by the company at a significance level of α=0.01 (Y/N)

Inspection of a random sample of 27 aircraft showed that 16 needed repairs to fix a wiring problem that might compromise safety. (a) How large a sample would be needed to estimate the true proportion of jets with the wiring problem, with 98 percent confidence and an error of ± 8 percent? (Enter your answer as a whole number (no decimals). Use a z-value taken to 3 decimal places in your calculations.)  Sample size      __________        (b) Would the airline actually conduct further sampling, or just inspect all the planes?   Conduct further sampling Inspect all the planes