Bolko saves $62 in 4 months. At this rate, how long will it take him to save $108.50?

Blakes goes from averaging 8 hours of sleep for a school night to averaging 6.5 hours of sleep on the weekend. What is the perce

beks73 [17]

Answer:

Step-by-step explanation:

So Blakes sleep 8 hours per night during the school day

8 hours/night...................................100%

6.5 hours/night...................................?

6.5*100/8=81.25

the change in percentage is 100-81.25=18.75%

the percentage change is 18.75

if it is easier for you, another method is:

8-6.5=1.5 subtract the original amount to the new amount

1.5/8=0.1875 divide by the original amount

0.1875*100=18.75 find the percentage

7 0

3 years ago

What does it mean when a researcher states that an observed effect or difference is significant with a confidence level of 99%?

icang [17]

Answer:

it affected more than half

Step-by-step explanation:

5 0

3 years ago

Read 2 more answers

Suppose that a college determines the following distribution for X = number of courses taken by a full-time student this semeste

lidiya [134]

Answer:

$E(X) = \sum_{i=1}^n X_i P(X_i) = 3*0.07 +4*0.4 +5*0.25 +6*0.28= 4.74$ In order to find the variance we need to calculate first the second moment given by:

$E(X^2) = \sum_{i=1}^n X^2_i P(X_i) = 3^2*0.07 +4^2*0.4 +5^2*0.25 +6^2*0.28= 23.36$ And the variance is given by:

$Var(X) = E(X^2) +[E(X)]^2 = 23.36 -[4.74]^2 = 0.8924$

And the deviation would be:

$Sd(X) =\sqrt{0.8924} =0.9447$

Step-by-step explanation:

Previous concepts

The expected value of a random variable X is the n-th moment about zero of a probability density function f(x) if X is continuous, or the weighted average for a discrete probability distribution, if X is discrete.

The variance of a random variable X represent the spread of the possible values of the variable. The variance of X is written as Var(X).

Solution to the problem

For this case we have the following distribution given:

X 3 4 5 6

P(X) 0.07 0.4 0.25 0.28

We can calculate the mean with the following formula:

$E(X) = \sum_{i=1}^n X_i P(X_i) = 3*0.07 +4*0.4 +5*0.25 +6*0.28= 4.74$

In order to find the variance we need to calculate first the second moment given by:

$E(X^2) = \sum_{i=1}^n X^2_i P(X_i) = 3^2*0.07 +4^2*0.4 +5^2*0.25 +6^2*0.28= 23.36$

And the variance is given by:

$Var(X) = E(X^2) +[E(X)]^2 = 23.36 -[4.74]^2 = 0.8924$

And the deviation would be:

$Sd(X) =\sqrt{0.8924} =0.9447$

3 0

3 years ago

What is equivalent to 4.321 × 10−4 ?<br><br> What is equivalent to 4.321 × 10−4 ?

Arlecino [84]

Please write that as 4.321 × 10^(−4). The " ^ " indicates exponentiation and the parentheses help make clear that your exponent here is a negative one.

Rewrite 4.321 × 10^(−4) by moving the decimal point 4 places to the left:

0.0004321

7 0

3 years ago

Please solve them I really need help

Ugo [173]

Answer:

Answers are below

Step-by-step explanation:

12) No because the scale factor is not the same between the two rectangles

13) Yes. TUV is congruent to XYZ. The scale factor is 3/4.

14) Yes. I used SAS to see whether or not the triangles were similar. PQR is congruent to UVW.

15) Yes. I used 14) Yes. I used SAS to see whether or not the triangles were similar. DGH is congruent to FEH.

8 0

3 years ago