Answer:
Sample size should be atleast 617
Step-by-step explanation:
given that a 95% confidence interval for the mean of a population is to be constructed and must be accurate to within 0.3 unit.
i.e. margin of error <0.3
Std devition sample = 3.8
For 95% assuming sample size large we can use z critical value
Z critical = 1.96
we have
Sample size should be atleast 617 to get an accurate margin of error 0.3
Ok so student in cleveland walks 2.5 miles away from cleveland every hour from 8
so the distance, x is x=2.5t
the riding one rides 4 hours later, so t-4
11 mph
y=11(t-4)
A. x=2.5t
y=11(t-4)
when do they meet is when the distance when they are equal or when x=y
2.5t=x=y=11(t-4)
solve for t
2.5t=11(t-4)
2.5t=11t-44
-8.5t=-44
divide both sides by -8.5
t=5.17647
answer is 5.18 hours
A.
x=2.5t
y=11(t-4)
B. 5.18 hours
Answer:
46.22
Step-by-step explanation:
Class A total= 23 x 13= 299
Clas B total= 57 x 28= 1596
total score= 299 + 1596 = 1895
total mean= 1895 ÷ (13+28) = 1895 ÷ 41
= 46.22
Answer:
Step-by-step explanation:
1) P= Area of Circle/ Area of large rectangle
Area of the circle = pi·r² = pi·2²=4 pi ft.²
Area of large rectangle= l·w -12·10 =120 ft.²
P = 4pi/120 rewrite 120 as 4·30
P= 4 pi/4*30 = pi/30 = 3.14/40 ≈ .1047 ≈10% (because .1047·100 =10.47≅10)
2) P = Area of smaller rectangle/ Area of large rectangle
Area of smaller rectangle = l·w = 2·4 =8 ft.²
Area of large rectangle=l·w = 12·10=120 ft²
P= 8/120 ≅ .0666≅ 7% (because .0666·100 =6.66≅7)
3) P= Not the circle or smaller rectangle/ Area of large rectangle
Not the circle or smaller rectangle area
= Area of large rectangle - Area of circle -Area of smaller rectangle
= 120 -4·pi -8 = 120 - (4· 3.14) -8 = 99.4362939 ft²
Area of large rectangle = l·w = 12·10 =120 ft²
P = 99.4362939 /120 ≅ .8286 ≅83% (because .8286·100 =82.86≅83)
