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1.Suppose babies born after a gestation period of 32 to 35 weeks have a mean wei

ID: 3178636 • Letter: 1

Question

1.Suppose babies born after a gestation period of 32 to 35 weeks have a mean weight of 2900

grams and a standard deviation of 700 grams while babies born after a gestation period of 40 weeks have a mean weight of 3300 grams and a standard deviation of 505 grams. If a 35-week gestation period baby weighs 2450 grams and a 40-week gestation period baby weighs 2850 grams, find the corresponding z-scores. Which baby weighs lessless relative to the gestation period?

The 35-week gestation period baby weighs ____ standard deviations_____the mean.

The 40-week gestation period baby weigh­­­s_______standard deviations________the mean.

2.Jamie has just completed her second semester in college. She earned a grade of C in her 3-hour

Calculus course, a grade of A in her 3-hour sociology course, a grade of D in her 3-hour chemistry

course, and a grade of B in her 5-hour art studio course. Assuming that A equals 4 points, B equals 3 points, C equals 2 points, D equals 1 point, and F is worth no points, determine Jamie's

grade-point average for the semester.

Jamie's grade point average is?

Round to two decimal places as needed

3. The accompanying frequency distribution represents the square footage of a random sample of 500 houses that are owner occupied year round. Approximate the mean and standard deviation square footage.

Square footage

Frequency

0minus49911,

9

500minus99911,

13

1,000minus1,499

33

1,500minus1,999

121

2,000minus2,499

119

2,500minus2,999

81

3,000minus3,499

47

3,500minus3,999

45

4,000minus4,499

22

4,500minus4,999

10

The mean square footage is?

4. At one point the average price of regular unleaded gasoline was $3.36 per gallon. Assume that the standard deviation price per gallon is $0.07 per gallon and use Chebyshev's inequality to answer the following.

(a) What percentage of gasoline stations had prices within 4 standard deviations of the mean?

(b) What percentage of gasoline stations had prices within 2.5 standard deviations of the mean? What are the gasoline prices that are within 2.5standard deviations of the mean?

(c) What is the minimum percentage of gasoline stations that had prices between $3.15 and

$3.57

At least _____% of gasoline stations had prices within 4 standard deviations of the mean.

(Round to the nearest hundredth as needed.)

5. The weight of an organ in adult males has a bell-shaped distribution with a mean of 330 grams and a standard deviation of 50 grams. Use the empirical rule to determine the following.

(a) About 99.7of organs will be between what weights?

(b) What percentage of organs weighs between 230 grams and 430 grams?

(c) What percentage of organs weighs less than 230 grams or more than 430 grams?

(d) What percentage of organs weighs between 280 grams and 480 grams?

______and_____grams (Use ascending order.)

Square footage

Frequency

0minus49911,

9

500minus99911,

13

1,000minus1,499

33

1,500minus1,999

121

2,000minus2,499

119

2,500minus2,999

81

3,000minus3,499

47

3,500minus3,999

45

4,000minus4,499

22

4,500minus4,999

10

Explanation / Answer

1. Here for gestation period of 32 to 35 babies mean weight is 2900 and sd=700, we need to find z score for weigh 2450 grams.

So z score=2450-2900/700=-0.64

Similarly for after a gestation period of 40 weeks babies mean weight is 3300 and sd=505, we need to find z score for weigh 2850 grams.

So z score=2850-3300/505=-0.89

We can see gestation period of 40 weeks are less relative