1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
vaieri [72.5K]
3 years ago
14

At her birthday​ party, Ms. Willow would not give her age directly. She​ said, 'If you add the year of my birth to this​ year, s

ubtract the year of my 25th birthday and the year of my 55th ​birthday, and then add my present​ age, the result is 58​.
Mathematics
1 answer:
Nimfa-mama [501]3 years ago
5 0

Answer:

69 years

Step-by-step explanation:

Given that:

Let year of birth = x

This year = 2020

Year of 25th birthday = x + 25

Year of 55th birthday = x + 55

Present age = 2020 - x

Hence,

x + 2020 - (x + 25 + x + 55) + (2020 - x) = 58

x + 2020 - (2x + 80) + (2020 - x) = 58

x + 2020 - 2x - 80 + 2020 - x = 58

-2x + 4040 - 80 = 58

-2x + 3960 = 58

-2x = 58 - 3960

-2x = - 3902

x = 1951

Birth year = 1951

,

Hence, age =

2020 - 1951 = 69 years

You might be interested in
1. The teacher assigns homework after 7/10
asambeis [7]

Answer:

B) Likely

Step-by-step explanation:

Unlikely = < 50%

Likely = > 50%

Certain = 100%

Equally likely = 50%

8 0
2 years ago
Which expression is equivalent to n + n - 0.18n?
horrorfan [7]

n + n - 0.18n

We can rewrite it as

2n - 0.18n

And if we solve it

(2 - 0.18)n = 1.82n

So the equivalente expression is B.

5 0
3 years ago
Read 2 more answers
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
HELP PLEASE! Will give out brainliest
charle [14.2K]

Answer:

i would say b but not sure

Step-by-step explanation:

hope this helps let me know if i got it wrong

4 0
3 years ago
ILL GIVE BRAINLIEST! HELP!
KonstantinChe [14]

Answer:

is B))))

Step-by-step explanation:

brainliest pls

.

.

.

.

.

7 0
2 years ago
Read 2 more answers
Other questions:
  • If you have 3896739272+13937383 what does it equal
    10·2 answers
  • For Halloween, 1/4 of the candy sold was chocolate. Of the chocolate sold, 7/8 was made by Nestle. What fraction of all the cand
    7·1 answer
  • What value of a makes the equation true?
    13·1 answer
  • 1,2,3,4,6and12 are all the factors of a number what is the number
    6·2 answers
  • Sal is tiling his entryway. The floor plan is drawn on a unit grid. Each unit length represents 1 foot. Tile costs $1.65 per squ
    13·1 answer
  • Find the length of x?
    8·1 answer
  • What is the Einstein theory
    11·1 answer
  • Can you answer this?
    13·1 answer
  • A person has 50,000 in taxable income for a year and pays a 10 percent income tax rate equal to 5,000 which action would reduce
    6·2 answers
  • About 58% of students go to a college within 100 miles of their home. If you choose a random sample of 10
    10·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!