Answer:
30 men
Step-by-step explanation:
In order to be sure that the sample mean does differ from the population mean by more than 0.90, the sample size (n) that should be used is given by:
Where 'Z' , for a 95% probability is 1.960, 's' is the standard deviation of 2.5 inches:
Rounding up to the nearest whole number, the sample size should be at least 30 men.
Answer:
$154.20
Step-by-step explanation:
To find a percent of a number, multiply the percent by the number.
20% of $771 =
= 20% * $771
= 0.2 * $771
= $154.20
The increase is $154.20
Answer:
circumference=
D
19.5=3.14*D
<u>19.5</u> =6
3.14
D=6
Radius=3
area=r²
3.14*3*3=28.26
area=28 inches
Step-by-step explanation:
Answer:
f(n) = -n^2 -3n +5
Step-by-step explanation:
Suppose the formula is ...
f(n) = an^2 +bn +c
Then we have ...
f(1) = 1 = a(1^2) +b(1) +c
f(2) = -5 = a(2^2) +b(2) +c
f(3) = -13 = a(3^2) +b(3) +c
__
Here's a way to solve these equations.
Subtract the first equation from the second:
-6 = 3a +b . . . . . 4th equation
Subtract the second equation from the third:
-8 = 5a +b . . . . . 5th equation
Subtract the fourth equation from the fifth:
-2 = 2a
a = -1
Then substituting into the 4th equation to find b, we have ...
-6 = 3(-1) +b
-3 = b
and ...
1 = -1 +(-3) +c . . . . . substituting "a" and "b" into the first equation
5 = c
The formula is ...
f(n) = -n^2 -3n +5
