(8x+4) - (3x-12) A. -5x - 16 B. 11x - 8 C. 5x + 16 D. 5x

Researchers at a medical school conducted a study to test the effectiveness of a new drug for lowering cholesterol. The 52 subje

Drupady [299]

Answer:

1. An Experimental

2. Dependent

3. Independent

Step-by-step explanation:

Considering the description of how the research was carried out, it can be concluded that This study is an example of AN EXPERIMENTAL study. This because the researcher is trying to study the effectiveness of a new drug for lowering cholesterol

The difference in cholesterol level is the DEPENDENT variable. This is because the difference in cholesterol level is what the researcher wants to determine.

The treatment with a drug or placebo is the INDEPENDENT variable. This is because this is what the researcher manipulates to determine the difference in cholesterol level which is the dependent variable in this experimental study.

4 0

3 years ago

Harry invests £6000 in a savings account.

zysi [14]

Step-by-step explanation:

here,

principal (p)=£6000

Rate (R)=. 3.4%

time (t)=3 yrs

now,

total investment is compound amount i.e CA

here,

$CA = p(1 + \frac{r}{100} ) ^{t}$

=£6000(1+3.4/100)^3

=£6633.044

here he will get his total investment as £6633.044 in compound interest of 3.4%

7 0

2 years ago

A carpenter is assigned the job of expanding a rectangular deck where the width is one-fourth the length. The length of the deck

leva [86]

Let the width be W, then the length is 4W (since the width is 1/4 the length)

The area of the original deck is $W*4W=4W^{2}$

The dimensions of the new deck are :

length = 4W+6
width=W+2

so the area of the new deck is :

$(4W+6)(W+2)= 4W^{2}+8W+6W+12= 4W^{2}+14W+12$

"the area of the new rectangular deck is 68 ft2 larger than the area of the original deck" means that we write the equation:

$4W^{2}+14W+12=68+4W^{2}$

$14W+12=68$

$14W=68-12=56$

$W= \frac{56}{14}= 4$

the length is $4W=4*4=16$ ft

Answer: width: 4, length: 16

3 0

3 years ago

Assuming that the population is normally distributed, construct a 9090% confidence interval for the population mean for each o

jasenka [17]

Given:

Set A: 1 4 4 4 5 5 5 8

Mean: 4.5

Standard dev: 1.9

Set B:

Mean: 4.5

Standard dev: 2.45

% = 90

Set A:

Standard Error, SE = s/ √n = 1.9/√8 = 0.67

Degrees of freedom = n - 1 = 8 -1 = 7

t- score = 1.89457861

Width of the confidence interval = t * SE = 1.89457861* 0.67 = 1.272685913

Lower Limit of the confidence interval = x-bar - width = 4.5 - 1.272685913 = 3.23

Upper Limit of the confidence interval = x-bar + width = 4.5 + 1.272685913 = 5.77

The 90% confidence interval is [3.23, 5.77]

Set B:

Standard Error, SE = s/ √n = 2.45/√8 = 0.87

Degrees of freedom = n - 1 = 8 -1 = 7

t- Score = 1.89457861

Width of the confidence interval = t * SE = 1.89457861* 0.87 = 1.641094994

Lower Limit of the confidence interval = x-bar - width = 4.5 - 1.641094994 = 2.86

Upper Limit of the confidence interval = x-bar + width = 4.5 + 1.641094994 = 6.14

The 90% confidence interval is [2.86, 6.14]

We can obviously see that sample B has more variation in the scores than sample A. The fact that the standard deviation is 2.45 for B and 1.9 for A). Therefore, they yield dissimilar confidence intervals even though they have the same mean and range.

6 0

3 years ago

A study showed that 25% of the students drive themselves to school. Based on the suggested probability, in a class of 18 student

Gwar [14]

Answer:

B) 0.283

Step-by-step explanation:

Binomial probability distribution

The binomial probability is the probability of exactly x successes on n repeated trials, and X can only have two outcomes.

$P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}$