Ask question

Ask question

All categories

1 year ago

15

Sanya noticed that the temperature was falling at a steady rate of 1.4 degrees every hour after the time that she first checked

her outdoor thermometer. By 6 a.m., the temperature had fallen 21 degrees. Which expression can you use to find how many hours earlier she had first checked the thermometer?
Negative 21 divided by negative 1.4
Negative 1.4 divided by negative 21
Negative 21 divided by 1.4
21 divided by negative 1.4

2 answers:

dalvyx [7]1 year ago

8 0

Answer:

The correct answer is: A

Step-by-step explanation:

I did the test on edge :>

kakasveta [241]1 year ago

4 0

Answer:A not b or c or d A!!

Step-by-step explanation:

You might be interested in

Find the value of 3 + 5 × (2 − 1).

Alenkasestr [34]

Step 1 (simplify):
3+5x(2-1)
8 x 1

Step 2 (solve):
8 x 1 = 8

8 is your answer. Hope this helps :)

8 0

1 year ago

Read 2 more answers

A nurse is preparing to administer dextrose 5% water (D5W) 250 ml IV to infuse over 2 hr. The nurse should set the IV pump to de

Molodets [167]

Answer:

the answer is 125

Step-by-step explanation:

I divided 250 and 2

125***ANSWER

4 0

2 years ago

"Consider the probability distribution of X, where X is the number of job applications completed by a college senior through the

Citrus2011 [14]

Answer:

Option b

Step-by-step explanation:

Given that the probability distribution of X, where X is the number of job applications completed by a college senior through the school’s career center.

Expected observed Diff

x p(x) p(x)*1000

0 0.002 2

1 0.011 11 14 -3

2 0.115 115 15 100

3 0.123 123 130 -7

4 0.144 144

5 0.189 189

6 0.238 238

7 0.178 178

1 1000

We find that there is a large difference in 2 job application

Hence option b is right.

4 0

1 year ago

To test whether or not there is a difference between treatments A, B, and C, a sample of 12 observations has been randomly assig

Keith_Richards [23]

Answer:

1. Null hypothesis: $\mu_{A}=\mu_{B}=\mu_{C}$

Alternative hypothesis: Not all the means are equal $\mu_{i}\neq \mu_{j}, i,j=A,B,C$

2. D. 36

3. C. 34

4. B. 1.059

5. B. 8.02

Step-by-step explanation:

Analysis of variance (ANOVA) "is used to analyze the differences among group means in a sample".

The sum of squares "is the sum of the square of variation, where variation is defined as the spread between each individual value and the grand mean"

Part 1

The hypothesis for this case are:

Null hypothesis: $\mu_{A}=\mu_{B}=\mu_{C}$

Alternative hypothesis: Not all the means are equal $\mu_{i}\neq \mu_{j}, i,j=A,B,C$

Part 2

In order to find the mean square between treatments (MSTR), we need to find first the sum of squares and the degrees of freedom.

If we assume that we have $p$ groups and on each group from $j=1,\dots,p$ we have $n_j$ individuals on each group we can define the following formulas of variation:

$SS_{total}=\sum_{j=1}^p \sum_{i=1}^{n_j} (x_{ij}-\bar x)^2$

$SS_{between}=SS_{model}=\sum_{j=1}^p n_j (\bar x_{j}-\bar x)^2$

$SS_{within}=SS_{error}=\sum_{j=1}^p \sum_{i=1}^{n_j} (x_{ij}-\bar x_j)^2$

And we have this property

$SST=SS_{between}+SS_{within}$

We need to find the mean for each group first and the grand mean.

$\bar X =\frac{\sum_{i=1}^n x_i}{n}$

If we apply the before formula we can find the mean for each group

$\bar X_A = 27$ , $\bar X_B = 24$ , $\bar X_C = 30$ . And the grand mean $\bar X = 27$

Now we can find the sum of squares between:

$SS_{between}=SS_{model}=\sum_{j=1}^p n_j (\bar x_{j}-\bar x)^2$

Each group have a sample size of 4 so then $n_j =4$

$SS_{between}=SS_{model}=4(27-27)^2 +4(24-27)^2 +4(30-27)^2=72$

The degrees of freedom for the variation Between is given by $df_{between}=k-1=3-1=2$ , Where k the number of groups k=3.

Now we can find the mean square between treatments (MSTR) we just need to use this formula:

$MSTR=\frac{SS_{between}}{k-1}=\frac{72}{2}=36$

D. 36

Part 3

For the mean square within treatments value first we need to find the sum of squares within and the degrees of freedom.

$SS_{within}=SS_{error}=\sum_{j=1}^p \sum_{i=1}^{n_j} (x_{ij}-\bar x_j)^2$

$SS_{error}=(20-27)^2 +(30-27)^2 +(25-27)^2 +(33-27)^2 +(22-24)^2 +(26-24)^2 +(20-24)^2 +(28-24)^2 +(40-30)^2 +(30-30)^2 +(28-30)^2 +(22-30)^2 =306$

And the degrees of freedom are given by:

$df_{within}=N-k =3*4 -3 = 12-3=9$ . N represent the total number of individuals we have 3 groups each one with a size of 4 individuals. And k the number of groups k=3.

And now we can find the mean square within treatments:

$MSE=\frac{SS_{within}}{N-k}=\frac{306}{9}=34$

C. 34

Part 4

The test statistic F is given by this formula:

$F=\frac{MSTR}{MSE}=\frac{36}{34}=1.059$

B. 1.059

Part 5

The critical value is from a F distribution with degrees of freedom in the numerator of 2 and on the denominator of 9 such that we have 0.01 of the area in the distribution on the right.

And we can use excel to find this critical value with this function:

"=F.INV(1-0.01,2,9)"

And we will see that the critical value is $F_{crit}=8.02$

B. 8.02

5 0

2 years ago

A football filters that is 60 m wide and 110 m long is being paved over to make a parking lot. The builder ordered 660,000,000 c

ad-work [718]

The answer is 10 cm

Imagine cement cover as a rectangle which volume is 660,000,000 cm3. So this rectangle has width (w = 60m), length (l = 110m), and height (h = ?). The height of the rectangle is actually a thickness of the cement layer. So, we will use the formula for the volume (V) of the rectangle to calculate the thickness:
V = w · l · h

It is given:
V = 660,000,000 cm³
w = 60 m = 60 · 100 cm = 6,000 cm
l = 110 m = 110 · 100 cm = 11,000 cm
h = ?

Using the formula: V = w · l · h
660,000,000 = 6,000 · 11,000 · h
660,000,000 = 66,000,000 · h
⇒ h = 660,000,000 ÷ 66,000,000 = 10 cm

4 0

1 year ago