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3 years ago

What is (3 − 5i) − (-2 − 5i)?

1 answer:

vladimir1956 [14]3 years ago

8 0

your answer is 5 bc you want to rearrange the numbers like this (5i - 5i) - (3 -(-2)) so (5i - 5i)= 0 and 3 - (-2) is 5

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An automobile manufacturer who wishes to advertise that one of its models achieves 30 mpg (miles per gallon) decides to carry ou

Katyanochek1 [597]

Answer:

$t=\frac{29.35-30}{\frac{1.365}{\sqrt{6}}}=-1.17$

$p_v =P(t_{(5)}$

If we compare the p value and the significance level given $\alpha=0.05$ we see that $p_v>\alpha$ so we can conclude that we have enough evidence to FAIL to reject the null hypothesis.

We can say that at 5% of significance the true mean is not significantly less than 30 so then the claim that true average fuel efficiency is (at least) 30 mpg makes sense

Step-by-step explanation:

Data given and notation

The mean and sample deviation can be calculated from the following formulas:

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

$s=\sqrt{\frac{\sum_{i=1}^n (x_i -\bar X)}{n-1}}$

$\bar X=29.35$ represent the sample mean

$s=1.365$ represent the sample standard deviation

$n=6$ sample size

$\mu_o =30$ represent the value that we want to test

$\alpha=0.05$ represent the significance level for the hypothesis test.

t would represent the statistic (variable of interest)

$p_v$ represent the p value for the test (variable of interest)

State the null and alternative hypotheses.

We need to conduct a hypothesis in order to check if the true mean is lower than 30 or no, the system of hypothesis are :

Null hypothesis: $\mu \geq 30$

Alternative hypothesis: $\mu < 30$

Since we don't know the population deviation, is better apply a t test to compare the actual mean to the reference value, and the statistic is given by:

$t=\frac{\bar X-\mu_o}{\frac{s}{\sqrt{n}}}$ (1)

t-test: "Is used to compare group means. Is one of the most common tests and is used to determine if the mean is (higher, less or not equal) to an specified value".

Calculate the statistic

We can replace in formula (1) the info given like this:

$t=\frac{29.35-30}{\frac{1.365}{\sqrt{6}}}=-1.17$

P-value

We need to calculate the degrees of freedom first given by:

$df=n-1=6-1=5$

Since is a one-side left tailed test the p value would given by:

$p_v =P(t_{(5)}$

Conclusion

If we compare the p value and the significance level given $\alpha=0.05$ we see that $p_v>\alpha$ so we can conclude that we have enough evidence to FAIL to reject the null hypothesis.

We can say that at 5% of significance the true mean is not significantly less than 30 so then the claim that true average fuel efficiency is (at least) 30 mpg makes sense

5 0

2 years ago

A recipe calls for 1 /4 start fraction, 1, divided by, 4, end fraction cup of chocolate chips for each batch of cookies. A

Neko [114]

Answer:

Step-by-step explanation:

1/2 cup = 2/4 cups = 2 × 1/4 cup

Alonzo can make 2 batches that each require 1/4 cup.

6 0

2 years ago

Tracy had a bag of candies, and none of the candies could be broken into pieces. She ate $\frac{1}{3}$ of them and then gave $\f

Ymorist [56]

Answer:

Step-by-step explanation:

Let the number of candies = n

Tracy ate = 1/3 of n = n/3 remaining 2n / 3

she gave 1/4 of the remainder to her friend = 1/4 of ( n - n/3) = 2n / 12

the new remainder = (2n / 3) - (2n / 12) = n /2

she and her mom then ate altogether = 30

and the brother took from 1 to five, the number he took = x

and she has 3 left

( n/2) - 30 - x = 3

n = 2 ( 33 + x)

now we know that the candies could not be broken and x is between 1 to 5

n = 2 (33 + 1), 2 (33+2), 2(33 +3), 2 (33+ 4) and 2 (33 + 5) this are the possible values of n, ( 68, 70, 72, 74, 76) and the multiple of 3 is 72

n therefore = 72

7 0

3 years ago

In a survey of 600 students in a school. 150 student were found to be taking tea and 225 taking coffee, 100 were taking both tea

EastWind [94]

Answer:

125

Step-by-step explanation:

600=150+225+100+X=475+X

600-475=125=X

X=125

7 0

2 years ago

Read 2 more answers

A sphere with a radical of 8.5cm

jek_recluse [69]

Take the common denominator and divide by 3

5 0

3 years ago