Answer:
r = 0.0424 cm (3sf)
Step-by-step explanation:
it makes 150 rev/sec
1 revolution = 1 circumference = 2pi*r
so every second the spool goes through 2*pi*r*150 of distance
we know that the rate of pulling is 40cm/sec
so 2pi*r*150 = 40
r = 40/(2pi*150), which is 0.04244131816 cm.
check: Circumference is 2pi*r = 0.2666
now multiply by 150rev/sec = 40 cm/sec
A. 10.3 assuming that 113.1 is given
Events are mutually exclusive only if they cannot both be true.
Only C is alright.
4 is a multiple of two so it can't be right.
Same logic works for B.
And then 2 is prime so then D is out too.
Multiplying or dividing two related quantities by the same number is called scaling
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