Answer:
Interval [16.34 , 21.43]
Step-by-step explanation:
First step. <u>Calculate the mean</u>

Second step. <u>Calculate the standard deviation</u>



As the number of data is less than 30, we must use the t-table to find the interval of confidence.
We have 6 observations, our level of confidence DF is then 6-1=5 and we want our area A to be 80% (0.08).
We must then choose t = 1.476 (see attachment)
Now, we use the formula that gives us the end points of the required interval

where n is the number of observations.
The extremes of the interval are then, rounded to the nearest hundreth, 16.34 and 21.43
118 text messages.
59.50-30=29.5
29.5 divided by 0.25=118.
I hope this is right! :) Sorry if it isn’t!
Step-by-step explanation:
y = 3 + 8x^(³/₂), 0 ≤ x ≤ 1
dy/dx = 12√x
Arc length is:
s = ∫ ds
s = ∫₀¹ √(1 + (dy/dx)²) dx
s = ∫₀¹ √(1 + (12√x)²) dx
s = ∫₀¹ √(1 + 144x) dx
If u = 1 + 144x, then du = 144 dx.
s = 1/144 ∫ √u du
s = 1/144 (⅔ u^(³/₂))
s = 1/216 u^(³/₂)
Substitute back:
s = 1/216 (1 + 144x)^(³/₂)
Evaluate between x=0 and x=1.
s = [1/216 (1 + 144)^(³/₂)] − [1/216 (1 + 0)^(³/₂)]
s = 1/216 (145)^(³/₂) − 1/216
s = (145√145 − 1) / 216
Answer: Janey has $115, and Teresa has $230.
Step-by-step explanation:
Set x be the money that Janey have, then Teresa have 2x.
x + 2x = 345
3x = 345
x= $115
2x= 2(115)= $230
<span>The tortoise crawls the whole 1000 m at 0.2 m/s, therefore, you must divide the distance by the rate of travel to find the time it took to complete the race. This gives us a time of 5,000 seconds to crawl the thousand meters. The hare runs the first 200 meters at 2 m/s, meaning that takes 100 seconds. The last 800 meters divided by the speed of 3 m/s gives us a time of 266 seconds. These two numbers must be added to the hare's rest time, converted from 1.3 hours into seconds by multiplying that number by 60 (for minutes in an hour) then 60 again (for seconds in a minute). 1.3 hours is equal to 4680 seconds. Therefore, the whole race took the hare 5,046 seconds, making it slightly slower than the hare, who finished in 5,000 seconds flat.</span>