Answer:
66 ≤ f ≤100
Explanation
Mean= ( Σ x ) / n
Mean= sum of scores/ number of subject she took
Now, she already too 3 subject which sum is 85+83+86=254
Now we need to know range of score for her to have (grade) a mark between 80 and 89
Now let take the lower limit mean=80
The lowest score she can get is
Mean = ( Σx) / n
80=(85+83+86+f)/4
80×4= 254+f
Therefore, f= 320-254=66
Therefore the minimum score she can have to have a B is 66.
Then, let take the upper limit mean 89. i.e the maximum she can have so that she don't have an A grade.
Mean = ( Σx) / n
89=( 83+85+86+f)/4
89×4= 254+f
f= 356-254
f=102.
Therefore this shows that she cannot have an A grade in the exam. The maximum score for the exam is 100.
There the range of score is 66 ≤ f ≤100 to have a B grade
66 ≤ f ≤100 answer
Since she cannot score 102 in the examination.
Answer: 45ft.
Step-by-step explanation:
Let assigned the value of x to the unknown lenght.
Therefore, the Length = xft
The with is 1/3 of the length and this. = 15ft.
Now , to get the length, we equate both together and then solve for x .
1/3 of x = 15
x/3 = 15
To get x, we multiply both side by 3
x = 45ft
The of the pool = 45ft.
Answer:
b ≈ 7.54 cm
Step-by-step explanation:
Pythagorean Theorem
a² + b² = c²
a and b are the sides and c is the hypotenuse
hypotenuse is 11 cm
a side is 8 cm
so
8² + b² = 11²
64 + b² = 121
-64 -64
b² = 57
√b² = √57
b ≈ 7.54 cm ( use ≈ because its rounded so its not exact)
Answer:
x= 3
Step-by-step explanation:
2x+3=9
2x = 6
x=6/2
x=3
Answer: 39x-45=15x-24
Step-by-step explanation:
Do inside brackets first then simplify
