subject-statistics

can you please answer this all questions

Question 17(1 point)

The patient recovery time from a particular surgical procedure is normally distributed with a mean of 5.3 days and a standard deviation of 2.1 days.

What is the probability of spending more than two days in recovery?

Question 17 options:

	0.0883
	0.9420
	0.8447
	0.0580

Question 18(1 point)

Which of the following represents a difference between continuous and discrete random variables?

Question 18 options:

	Probability for continuous random variables means finding the area under a curve, while for discrete random variables it means summing individual probabilities
	Continuous random variables assume an uncountable number of values, and discrete random variables do not
	The probability for any individual value of a continuous random variable is zero, but for discrete random variables it is not
	All of these choices are true

Question 19(1 point)

The U.S. Census Bureau conducts a study to determine the time needed to complete the short form. The Bureau surveys 200 people. The sample mean is 8.2 minutes. There is a known standard deviation of 2.2 minutes. The population distribution is assumed to be normal.

If the Census wants to increase its level of confidence and keep the error bound the same by taking another survey, what changes should it make?

Question 19 options:

	The Census should survey more people. When we keep the same error bound, the confidence level increases.
	The Census should survey more people. When we keep the same error bound, the confidence level decreases.
	The Census should survey fewer people. When we keep the same error bound, the confidence level decreases.
	The Census should survey fewer people. When we keep the same error bound, the confidence level increases.

Question 20(1 point)

Of 1,050 randomly selected adults, 360 identified themselves as manual laborers, 280 identified themselves as non-manual wage earners, 250 identified themselves as mid-level managers, and 160 identified themselves as executives. In the survey, 82% of manual laborers preferred trucks, 62% of non-manual wage earners preferred trucks, 54% of mid-level managers preferred trucks, and 26% of executives preferred trucks.

We are interested in finding the 95% confidence interval for the percent of executives who prefer trucks.

Construct a 95% confidence interval. State the confidence interval, sketch the graph, and calculate the error bound.

Question 20 options:

	CI: (0.19432, 0.33068) Figure 8.16 EBM: 0.0707
	CI: (239.84, 248.16) EBM= 4.16
	CI: (7.9441, 8.4559) Figure 8.11 EBM= 0.26

Question 21(1 point)

Lesley E. Tan investigated the relationship between left-handedness vs. right-handedness and motor competence in preschool children. Random samples of 41 left-handed preschool children and 41 right-handed preschool children were given several tests of motor skills to determine if there is evidence of a difference between the children based on this experiment. The experiment produced the means and standard deviations shownTable 10.26. Determine the appropriate test and best distribution to use for that test.

	Left-handed	Right-handed
Sample size	41	41
Sample mean	97.5	98.1
Sample standard deviation	17.5	19.2

Question 21 options:

	Two independent means, Student's-t distribution
	Matched or paired samples, Student's-t distribution
	Two population proportions, normal distribution
	Two independent means, normal distribution

Question 22(1 point)

It is believed that Lake Tahoe Community College (LTCC) Intermediate Algebra students get less than seven hours of sleep per night, on average. A survey of 22 LTCC Intermediate Algebra students generated a mean of 7.24 hours with a standard deviation of 1.93 hours. At a level of significance of 5%, do LTCC Intermediate Algebra students get less than seven hours of sleep per night, on average?

The Type II error is not to reject that the mean number of hours of sleep LTCC students get per night is at least seven when, in fact, the mean number of hours

Question 22 options:

	is less than seven hours.
	is at most seven hours.
	is more than seven hours.
	is at least seven hours.

Question 23(1 point)

In a given group, the correlation between height measured in feet and weight measured in pounds is +.68. Which of the following would alter the value of r?

Question 23 options:

	height is expressed centimeters.
	weight is expressed in Kilograms.
	both of the above will affect r.
	neither of the above changes will affect r.

Question 24(1 point)

An interpretation of r=0.5 is that the following part of the Y-variation is associated with which variation in X:

Question 24 options:

	most
	half
	very little
	one quarter
	none of these

Question 25(1 point)

A bottle of water is labeled as containing 16 fluid ounces of water. You believe it is less than that. What type of test would you use?

Question 25 options:

	Not enough information to answer
	a two-tailed test.
	a left-tailed test
	a right-tailed test

Question 26(1 point)

A statistics instructor believes that fewer than 20% of Evergreen Valley College (EVC) students attended the opening night midnight showing of the latest Harry Potter movie. She surveys 84 of her students and finds that 11 attended the midnight showing. An appropriate alternative hypothesis is:

Question 26 options:

	p = 0.20
	p 0.20
	p < 0.20
	p > 0.20

Question 27(1 point)

An archaeologist is calculating the distribution of the frequency of the number of artifacts she finds in a dig site. Based on previous digs, the archaeologist creates an expected distribution broken down by grid sections in the dig site. Once the site has been fully excavated, she compares the actual number of artifacts found in each grid section to see if her expectation was accurate. What type of test should they use?

Question 27 options:

	Goodness-of-Fit Test
	Test of a Single Variance
	Test of Independence
	Test for Homogeneity

Question 28(1 point)

Groups of men from three different areas of the country are to be tested for mean weight. The entries inTable 12.13are the weights for the different groups.

Group 1	Group 2	Group 3
216	202	170
198	213	165
240	284	182
187	228	197
176	210	201

Table12.13

What is the Sum of Squares Factor?

Question 28 options:

	660.03
	7920.4
	4939.2
	2469.6

Question 29(1 point)

Two students are interested in whether or not there is variation in their test scores for math class. There are 15 total math tests they have taken so far. The first student's grades have a standard deviation of 38.1. The second student's grades have a standard deviation of 22.5. The second student thinks his scores are more consistent.

At the 5% significance level, do we reject the null hypothesis?

Question 29 options:

	not enough information to compute @ 5% confidence
	Cannot reject the null hypothesis. There is not enough evidence to say that the variance of the grades for the first student is higher than the variance in the grades for the second student.
	Cannot accept the null hypothesis. There is enough evidence to say that the variance of the grades for the first student is higher than the variance in the grades for the second student.

Question 30(1 point)

Determine the appropriate test to be used. A marathon runner is interested in the relationship between the brand of shoes runners wear and their run times. She takes a random sample of 50 runners and records their run times as well as the brand of shoes they were wearing.

Question 30 options:

	Test of Independence
	Test of a Single Variance
	Goodness-of-Fit Test
	Test for Homogeneity

Question 31(1 point)

You are testing that the mean speed of your cable Internet connection is more than three Megabits per second. State the null and alternative hypotheses.

Question 31 options:

	H0: 4 Ha: < 4
	H0:= 15 Ha: 15
	H0: 3 Ha: < 3
	H0: = 3 Ha: 3

Question 32(1 point)

The league mean batting average is 0.280 with a known standard deviation of 0.06. The Rattlers and the Vikings belong to the league. The mean batting average for a sample of eight Rattlers is 0.210, and the mean batting average for a sample of eight Vikings is 0.260. There are 24 players on the Rattlers and 19 players on the Vikings. Are the batting averages of the Rattlers and Vikings statistically different?

Which of the following choices best identifies the hypothesis test.

Question 32 options:

	matched or paired samples
	independent group means, population standard deviations and/or variances known
	two proportions
	single proportion
	single mean
	independent group means, population standard deviations and/or variances unknown

Question 33(1 point)

Consider a sample least squares regression analysis between a dependent variable (Y) and an independent variable (X). A sample correlation coefficient of 1 (minus one) tells us that

Question 33 options:

	there is a perfect negative relationship between and X in the population
	there is a perfect negative relationship between Y and X in the sample.
	there is no relationship between Y and X in the population
	there is no relationship between Y and X in the sample

Question 34(1 point)

Under a "scatter diagram" there is a notation that the coefficient of correlation is .10. What does this mean?

Question 34 options:

	one-tenth of the variance of one variable is shared with the other variable
	one-tenth of one variable is caused by the other variable
	plus and minus 10% from the means includes about 68% of the cases
	on a scale from -1 to +1, the degree of linear relationship between the two variables is +.10