Suppose you work for the Department of Natural Resources and you want to estimate, with 95% confidence, the mean (average) length of all walleye fingerlings in a fish hatchery pond. You take a random sample of 36 fingerlings and determine that the average length is 7.4 inches and the population standard deviation is known to be 1.9 inches. a. Construct a 95% confidence interval.
b. Interpret the Confidence Interval:
c. If the hatchery supervisor claimed that the average length of the walleye fingerlings fish is more than 7.5 inches, would you agree or disagree?

a)    

b) For this case we can conclude that at 95% of confidence the true mean for the lenght of all welleye fingerprints in a fish hatchery pond is between 6.78 and 8.02

c) For this case since the value of 7.5 is included in the confidence interval we don't have enough evidence to conclude that the true mean is actually higher than 7.5 inches

Step-by-step explanation:

Information given

represent the sample mean

population mean (variable of interest)

represent the population standard deviation

n=36 represent the sample size  

Part a

The confidence interval for the mean is given by :

  (1)

The Confidence is 0.95 or 95%, the significance is and , and the critical value would be

Replacing the info we got:

Part b

For this case we can conclude that at 95% of confidence the true mean for the lenght of all welleye fingerprints in a fish hatchery pond is between 6.78 and 8.02

Part c

For this case since the value of 7.5 is included in the confidence interval we don't have enough evidence to conclude that the true mean is actually higher than 7.5 inches

a) $ 9.50

b) 17

c) y-intercept (0, 12). this is the initial amount of money that joe had prior to playing any game.

d) x-intercept ( 24, 0). this is the number of games that joe will play before he depletes the initial amount of money that he had.

e) slope is -0.5. joe's balance will reduce by 0.5 for every game that he plays.

f)

domain; [0,24]

range; [0,12]

g) x + 2y = 24

step-by-step explanation:

a)

if joe plays 5 games, this will imply that x = 5. substitute x = 5 in the equation and solve for y;

y = -.50x + 12

y = -0.50(5) + 12

y = 9.50

b)

if joe leaves the arcade with $3.50, this will mean that y = 3.50. plug in y = 3.50 in the given equation and solve for x;

y = -.50x + 12

3.50 = -0.50x + 12

0.50x = 12 - 3.50

0.5x = 8.5

x = 17

c)

the function given is   y = -.50x + 12.

the y-intercept is the point where the graph of this function will intersect the y-axis. at this point, the value of x is usually 0. plug in x = 0 in the given equation and determine y;

y = -0.50(0) + 12

y = 12

the y-intercept is thus (0, 12). this is the initial amount of money that joe had prior to playing any game.

d)

the x-intercept refers to the point where the graph of a function intersects with the x-axis. at this point, the value of y is 0. substitute y = 0 in the given equation and solve for x;

0 =   -.50x + 12

0.5x = 12

x = 24

x-intercept ( 24, 0). this is the number of games that joe will play before he depletes the initial amount of money that he had.

e)

the slope of the given equation is -0.5. the equation has been given in slope-intercept form. thus the slope is simply the coefficient of x.

joe's balance will reduce by 0.5 for every game that he plays. this is the interpretation of the slope.

f)

domain is the set of x values for which the function is real and defined. the domain will thus be; [0,24]. this will restrict the balance to only assume positive values.

on the other hand, the range is the set of y values for which a function is real and defined. the range in our case will be [0,12]. joe can have between $0 and $12 balance.

g)

the standard form of the equation of a straight line is;

ax + by = c

where a, b, and c are integers.

our equation is given as;

y = -.50x + 12

re-writing the equation we have;

0.5x + y = 12

divide all through by 0.5;

x + 2y = 24