Answer:
(30.09, 32.91)
Step-by-step explanation:
Mean number of pounds of trash = x = 31.5 pounds
Standard deviation = s = 7.8 pounds
Sample size = n = 120
Confidence level = 95%
Since, we are given the sample standard deviation instead of the population standard deviation, we will use t-test to find the confidence interval.
Degrees of freedom = df = n - 1 = 120 - 1 = 119
The t-value associated with 95% confidence interval and df=119 from the t-table comes out to be:
t = 1.98
The formula to calculate the confidence interval is:
Using the values in above expression we get:
Thus, the 95% confidence interval for the mean number of lbs of trash per person per week that is generated in the city is (30.09, 32.91)
Answer:
Option B. y = 2x; 20 feet
Step-by-step explanation:
1. Determination of the equation that represents the relationship.
Let y be the distance travelled.
Let x be the time taken.
Let K be the speed.
From the question given above, the following data were obtained:
Distance (y) = 80 ft
Time (x) = 40 s
Speed (k) =.?
Speed = Distance /time
K = y/x ......... (1)
K = 80/40
K = 2 ft/s
Substitute the value of k into equation 1
K = y/x
K = 2 ft/s
2 = y/x
Cross multiply
y = 2x
Therefore, the equation that represents the relationship is y = 2x
2. Determination of the distance travelled in 10 s.
Speed (k) = 2 ft/s
Time (x) = 10 s
Distance (y) =.?
y = 2x
y = 2 × 10
y = 20 ft
Therefore, the person will travel 20 feet in 10 seconds.
From the above calculations, the right answer to the question is
Option B. y = 2x; 20 feet
Answer: 
Step-by-step explanation:
<u>Use trigonometry (shown in image below) to find the 3 side-lengths:</u>
- The side opposite of θ =
- The base side adjacent to θ = 11
- The hypotenuse = 12
<u>According to right triangle trigonometry:</u>
cos θ = 
<u>Substitute in the values:</u>
cos θ =
Answer: 1/250
Step-by-step explanation:
Given the recurring decimal : 0.004
Firstly:
Let x = 0.004 - - - (1)
Due to the number of decimals places and value of x;
We multiply (1) by 1000 to obtain an integer
Multiply (1) by 1000
1000x = 4 - - - (2)
From (2) we can solve for x and leave our answer as a fraction.
Divide (2) by 1000 to obtain the value of x
1000x / 1000 = 4 / 1000
x = 1 / 250
Recall x = 0.004
Therefore, x = 0.004 = 1/250
