Answer:
68.26% of the parts will have lengths between 3.8 in. and 4.2 in.
Step-by-step explanation:
The lengths of a lawn mower part are approximately normally distributed

Standard deviation =
We are supposed to find What percentage of the parts will have lengths between 3.8 in. and 4.2 in . i.e. P(3.8<x<4.2)
Formula : 
At x = 3.8

Z=-1
Refer the z table for p value
p value =0.1587
At x =4.2

Z=1
Refer the z table for p value
p value =0.8413
P(3.8<x<4.2)=P(x<4.2)-P(x<3.8)=0.8413-0.1587=0.6826
So, 68.26% of the parts will have lengths between 3.8 in. and 4.2 in.
the unscented candles burn faster at a rate of (1/3) inches/ hour
Step-by-step explanation:
scented candles:
(1/12) / (20/60) = 1/4 inches/ hour
unscented candles:
(1/6) / (30/ 60) = 1/3 inches/ hour
hope it helps!
Answer: 2285
Step-by-step explanation:
Formula to find the sample size is given by :-

, where p = prior estimate of population proportion.
E= Margin of error.
= z-value for confidence interval of c.
Given : Confidence interval : 95%
From the z-value table , the z-value for 95% confidence interval = 
The General Social Survey reported a sample where about 61% of US residents thought marijuana should be made legal.
i.e. the prior estimate of population proportion of US residents thought marijuana should be made legal : p=0.61
[∵ sample proportion is the best estimate for population proportion.]
Margin of error : E= 2%=0.02
Now, the required minimum sample size would be :-

Simplify ,

Thus , we need to survey <u>2285</u> Americans .
98% are located each day for a total of 24,500 pieces of found luggage, but lost each day would be 500 pieces of luggage.