Answer:
Step-by-step explanation:
3) diameter of penny = 19 mm
r = 19/2 = 9.5 mm
Area of penny = πr²
= 3.14 * 9.5 * 9.5
= 283.385
= 283.39 mm²
Diameter of nickel = 21 mm
r = 21/2 = 10.5 mm
Area of nickel = πr²
= 3.14 * 10.5 *10.5
= 346.185
= 346.19 mm²
346.19 - 283.39 = 62.8 mm²
Area of Canadian nickel is greater than Canadian penny by 32.6 mm²
4) r = 12 mm
Area of circle = πr²
= 3.14 * 12 * 12
= 452.16 mm²
5) r = 20 cm
Area of circle = πr²
= 3.14 * 20 * 20
= 1256 cm²
Answer:
(53.812 ; 58.188) ; 156
Step-by-step explanation:
Given that :
Sample size (n) = 51
Mean (m) = 56
Standard deviation (σ) = 9.5
α = 90%
Using the relation :
Confidence interval = mean ± Error
Error = Zcritical * (standard deviation / sqrt (n))
Zcritical at 90% = 1.645
Error = 1.645 * (9.5 / sqrt(51))
Error = 1.645 * 1.3302660
Error = 2.1882877
Hence,
Confidence interval :
Lower boundary = 56 - 2.1882877 = 53.8117123
Upper boundary = 56 + 2.1882877 = 58.1882877
Confidence interval = (53.812 ; 58.188)
2.)
Margin of Error (ME) = 1.25
α = 90%
Sample size = ((Zcritical * σ) / ME)^2
Zcritical at 90% = 1.645
Sample size = ((1.645 * 9.5) / 1.25)^2
Sample size = (15.6275 / 1.25)^2
Sample size = 12.502^2 = 156.3000
Sample size = 156
Answer:
22.8 and 37.5
Step-by-step explanation:
Given the
The weights (in pounds) of 18 preschool children are
32, 20, 25, 27, 31, 22, 30, 23, 44, 37, 33, 45, 41, 24, 34, 21, 39, 29
To find its 20th percentile and 75th percentile.
In ascending order we get like this
Position X (Asc. Order)
1 20
2 21
3 22
4 23
5 24
6 25
7 27
8 29
9 30
10 31
11 32
12 33
13 34
14 37
15 39
16 41
17 44
18 45
Percentile position = (no of entries +1)20/100 = 19/5 = 3.8
Since posiiton is not integer we use interpolation method.
The value of 3.8 - 3 = 0.8 corresponds to the proportion of the distance between 22 and 23 where the percentile we are looking for is located at.
Hence 20th percentile = 
So answer is 22.8
----------------------
75th percentile
Percentile posiiton = 19(75)/100 = 14.25
75th percentile= 
Answer:
65 miles
Step-by-step explanation:
There are two simultaneous equations
. Remeber that v=d/t, 1hour = 60 minutes.
1. 40 = (d+15)/(t+0.5)
2. 50 = d/t
solving: d= 25 miles and t=0.5 hours.
The distance traveled is:
D=d+d+15
D=65 miles
