Statistics

Acid rain question Identify the slope of the line and explain what it means in this setting

-0.0053. For each additional week in the study, the predicted pH decreased by 0.0053 units.

If we select a student from the school at random, what is the probability that the student is: b) someone who eats breakfast regularly?

.5402

The probability of finding 3 people in a household is the same as the probability of finding 4 people.These probabilities are marked "???" in the table of the distribution. The probability that a household contains 3 people must be

0.16

If we select a student from the school at random, what is the probability that the student is: Female?

0.4622

What is the correlation r for this data set?

0.99

Of a sample of 275 students, 20 say they are vegetarians. Of these, 9 eat both fish and eggs, 3 eat eggs but not fish, and 7 eat neither. If we choose one of those 275 students at random and the chosen student turns out to be a vegetarian, what is the probability that the chosen student eats neither fish nor eggs?

13/20

What is the standard deviation of all the heights of the show dogs?

147.323

What is the standard deviation of the weights of the packed boxes?

2.021

What is the variance of all the heights of the show dogs?

27129.999

Acid rain question According to the regression line, what was the pH at the end of this study?

4.635

The scores on the real estate licensing examination given in a particular state are normally distributed with a standard deviation of 70. What is the mean test score if 25% of applicants score above 475

428

Acid rain question Identify the y intercept of the line and explain what it means in this setting

5.43. The predicted pH level at the beginning of the study (weeks=0) is 5.43.

The expected profit when playing the raffle is:

585

The height of American men aged 18 to 24 are approximately normal with a mean of 68 inches and a standard deviation of 2.5 inches. About 20% of these men are taller than.

70 inches

5. In addition to the regression line, the report on the Mumbai measurements says that r^2 = 0.95. This suggests that

95% of the variation in height is accounted for by the regression line

Find the mean and standard deviation if the results of the two dice are added.

B) = 9, = 3.341

Section 6.3 MC: Geometric settings...

B) do not have a fixed number of trials

Question 7) Create a survey and explain how you would collect a cluster sample and a strata sample.

Concert example

Section 6.3 MC: Determine the probability that the coin comes up tails AT LEAST 15 times.

D) 0.0207

Question 5) After a frost warning was issued, the owner of a large orange grove asked his workers to spray all his trees with water. The water was supposed to freeze and form a protective covering of ice around the orange blossoms. Nevertheless, the owner suspected that some trees suffered considerable damage due to the frost. To estimate the proportion of trees that suffered more than 50 percent damage due to the frost, he took a random sample of 100 trees from his grove. What is the response variable in this experiment?

For each sampled tree, whether it suffered more than 50 percent damage or at most 50 percent damage

The percent of weeds that grew in each plot was recorded. Here are some boxplots of the results. Which of the following is not a correct statement about the results of this experiment?

High and low concentrations of either chemical have approximately the same effects on weed growth.

Question 6) Create a survey and describe your population, sample, how you would go about taking the survey to avoid bias. Also include an example of how you could go wrong while collecting data.

I want to know what the school thinks about the new volleyball coach. The school has 400 students on total, being my population, but I'm only planning on surveying 50 students, being my sample. I would avoid basis by assigning the whole population numbers 1-400, and then I would put the numbers in a hat, shake it up, pull out 50 numbers, and only survey those students. A poor way to collect data would be if I only surveyed boys on the soccer team about their opinion of the volleyball coach, their opinions won't accurately represent the whole school.

(c) The histogram suggests that there may be outliers. Use the 1.5 x IQR rule of thumb to show that no values in this distribution meet this criterion for outliers.

IQR = 41.63 - 2.23 = 39.40 1.5 x IQR = 59.10 Q1 - 59.10 is less than 0 so there are no low outliers. Q3 + 59.10 = 100.73, so there are no high outliers

Give the five-number summary, and explain why you can see from these five numbers that the distribution is strongly skewed to the right.

Min = 0 Q1 = 2.23 Med = 12.66 Q3 = 41.63 Max = 88.6 . The distance from the median to Q3 is much greater than the distance from the median to Q1, and the distance from Q3 to the maximum is much greater than the distance from Q1 to the minimum. Both of these comparisons indicate that the distribution is skewed to the right

4. You use the same bar of soap to shower each morning. The bar weighs 80 grams when it is new. It's weight goes down by 6 grams per day on average. What is the equation of the regression line for predicting weight from days of use?

Predicted weight= 80-6x (x=days)

b) Describe the overall pattern of the distribution and any departures from that pattern.

Skewed right with gaps between 3 & 4.4 and from 6.2 to 7.5. The spread is from 1.1 to 7.5. There appears to be one outlier 7.5. The center is about 2.4.

(a) Describe the important features of this distribution. What does it tell you about how the economic burden of tornados is distributed among the states?

The distribution of damages ranges from near $0 to near $90 million. This suggests that many states suffered very little damage, but a small number of states suffered a great deal of damage

The fraction of the variation in the values of y that is explained by the least-squares regression of y on x is...

the square of the correlation coefficient