HELP ASAP!!! (The problem is on a screenshot)

Find the sum of the summation of 3 i minus 15, from i equals 2 to 7.

Mrac [35]

The summation symbol means we use the variable i in the equation from the given range. In this case, we are given with the equation 3 i - 15 and i ranges from 2 to 7. The summation using simply the calculator is equal to -9. The answer to this problem is -9.

3 0

3 years ago

Read 2 more answers

An online camping supplies outlet charges $14 for a canteen,

Vedmedyk [2.9K]

Answer:

Part A: 14x + 2

Part B: CJ's order is $30, and Cameron's order is $58.

Step-by-step explanation:

<u>Part A:</u> The total cost of the order would be $14 multiplied by the amount of canteens, plus the shipping price of $2. This is what my expression represents.

CJ's Order:

14(2) + 2 =

28 + 2

$30

Cameron's Order:

14(4) + 2 =

56 + 2 =

$58

Hope this helps! :D

3 0

3 years ago

The route used by a certain motorist in commuting to work contains two intersections with traffic signals. The probability that

tekilochka [14]

Answer:

a) P(X∩Y) = 0.2

b) $P_1$ = 0.16

c) P = 0.47

Step-by-step explanation:

Let's call X the event that the motorist must stop at the first signal and Y the event that the motorist must stop at the second signal.

So, P(X) = 0.36, P(Y) = 0.51 and P(X∪Y) = 0.67

Then, the probability P(X∩Y) that the motorist must stop at both signal can be calculated as:

P(X∩Y) = P(X) + P(Y) - P(X∪Y)

P(X∩Y) = 0.36 + 0.51 - 0.67

P(X∩Y) = 0.2

On the other hand, the probability $P_1$ that he must stop at the first signal but not at the second one can be calculated as:

$P_1$ = P(X) - P(X∩Y)

$P_1$ = 0.36 - 0.2 = 0.16

At the same way, the probability $P_2$ that he must stop at the second signal but not at the first one can be calculated as:

$P_2$ = P(Y) - P(X∩Y)

$P_2$ = 0.51 - 0.2 = 0.31

So, the probability that he must stop at exactly one signal is:

$P = P_1+P_2\\P=0.16+0.31\\P=0.47$

7 0

3 years ago

A 90-kg astronaut biologist searches for microbial life on Mars where the gravitational acceleration is g = 3.71 m/s2. What is t

Yuki888 [10]

M = 90 kg,
On Mars: g = 3.71 m/s²
Weight = m · g = 90 kg · 3.71 m/s² = 333.9 N
1 N = 0.2248 lbf
333.9 · 0.2248 = 75.06072 lbf ≈ 75 lbf

5 0

3 years ago

Eric is studying people's typing habits. He surveyed 525 people and asked whether they leave one space or two spaces after a per

Otrada [13]

Answer: (0.8115, 0.8645)

Step-by-step explanation:

Let p be the proportion of people who leave one space after a period.

Given: Sample size : n= 525

Number of people responded that they leave one space. =440

i.e. sample proportion: $\hat{p}=\dfrac{440}{525}\approx0.838$

z-score for 90% confidence level : 1.645

Formula to find the confidence interval :

$\hat{p}\pm z^*\sqrt{\dfrac{\hat{p}(1-\hat{p})}{n}}$

$0.838\pm (1.645)\sqrt{\dfrac{0.838(1-0.838)}{525}}\\\\=0.838\pm (1.645)\sqrt{0.00025858285}\\\\=0.838\pm (1.645)(0.01608)\\\\= 0.838\pm0.0265\\\\=(0.838-0.0265,\ 0.838+0.0265)\\\\=(0.8115,\ 0.8645)$

Hence, a 90% confidence interval for the proportion of people who leave one space after a period: (0.8115, 0.8645)

3 0

3 years ago