Answer:
option (a) It will be closer to 30 than to 20
Step-by-step explanation:
Data provided in the question:
For sample 1:
n₁ = 10
variance, s₁² = 20
For sample 2:
n₂ = 15
variance, s₂² = 30
Now,
The pooled variance is calculated using the formula,

on substituting the given respective values, we get

or
= 26.0869
Hence,
the pooled variance will be closer to 30 than to 20
Therefore,
The correct answer is option (a) It will be closer to 30 than to 20
Answer:
10x=4
x=4/10
x=2/5
Step-by-step explanation:
Let x be the number of bags of Nature's Recipe Venison Meal & Rice Canine 20 percent protein, y be the number of bags of Nutro Max Natural Dog Food 27 percent protein and z be the number of bags of PetSmart Premier Oven Baked Lamb 25 percent protein a dog breeder buys. He wants to make 300 pounds of a mix. Then
20x+17.5y+30z=300.
Now
- in 20x pounds of Nature's Recipe Venison Meal & Rice Canine 20 percent protein is 0.2·20x=4x pounds of protein;
- in 17.5y pounds of Nutro Max Natural Dog Food 27 percent protein is 0.27·17.5y=4.725y pounds of protein;
- in 30z pounds of PetSmart Premier Oven Baked Lamb 25 percent protein is 0.25·30z=7.5z pounds of protein;
- in 300 pounds of mix containing 22 percent protein is 0.22·300=66 pounds of protein.
Then 4x+4.725y+7.5z=66.
You get a system

From the first equation
Substitute it into the second equation:

Simplify it:

y must be divided by 20, then
- y=0, x=9, z=10-6=4;
- y=20, x=16, z is not a whole number;
- y=40, x=23, z is not a whole number;
- y=60, x=30, z=10-20-35<0;
- thus, all other possible z will be <0.
Answer: 9 bags with 1st mix, 0 bags with 2nd mix and 4 bags with 3rd mix.
1mile=5.280
6miles=6*5.280
= 31.680
So option B is the answer...
If this helps you plzz Mark me as brainlest...
1 dozen = 12
144 / 12 = 12 dozen
12 dozen/ 3 = 4
They need 4 times the amount of flour:
3 1/4 x 4 = 13
They need 13 cups of flour