What is the temperature at 10 yards belowthe surface

A car's speedometer has a percent error of 5%. The speedometer currently shows that the car is traveling at a speed of 60 mph.

Minchanka [31]

Answer:

The actual speed of the car is either 57 mph or 63 mph

Step-by-step explanation:

Given as :

The measured speed o the car = 60 mph

The percentage error in speedometer = 5 %

Let The actual speed of car = x mph

Now, percentage error = $\dfrac{\textrm actual value - \textrm measured value}{\textrm measured value}$ × 100

So, $\frac{5}{100}$ = $\frac{x - 60}{60}$

or, $\frac{5}{100}$ × 60 = x - 60

Or, 3 = x - 60

∴ x = 63 mph

Hence The actual speed of the car is either 57 mph or 63 mph . Answer

8 0

3 years ago

Assume every 10-digit natural number is a possible telephone number except those that begin with 0, 1 or 2. What fraction of tel

lana [24]

Answer: 1/70

Step-by-step explanation:

This is a question that can also be interpreted as what is the probability of having the first number of a phone number to be 8 and the last number of the phone number to also be 8. This answer gives the fraction of the phone numbers that starts with 8 and end with 8.

Since three numbers (0,1,2) cannot start a phone number and we are left to pick from 7 numbers,

then the probability of figure "8" starting phone number = 1/7

Since all 10 numbers can possibly end a phone number,

then the probability of having figure "8" as the last digit of a phone number = 1/10

Hence probability of having "8" as the first and last digit of a phone number = fraction of total telephone numbers that begin with digit 8 and end with digit 8 = 1/7 × 1/10 = 1/70.

5 0

3 years ago

20 POINTS An electrician charges a set fee for every house call and then charges an hourly rate depending on how long the job ta

tatuchka [14]

Answer:

$the \: slope \: is \to \boxed{60}$

Step-by-step explanation:

$if \to C=65+60t \\ C=60t + 65 \\ but \: the \: \boxed{ c - intercept} \: is \: in \: the \: form \to \\ c = mt + b \\ hence \to \\ 60t = mt \\ m = \frac{60t}{t} \\ m = 60 \\ the \: slope \: is \to \boxed{60}$

5 0

3 years ago

Read 2 more answers

Simplify 0, -6 please :(

snow_tiger [21]

Answer:

You cant simplify it??????

Step-by-step explanation:

3 0

3 years ago

Read 2 more answers

Consider a chemical company that wishes to determine whether a new catalyst, catalyst XA-100, changes the mean hourly yield of i

kolezko [41]

Answer:

Null hypothesis: $\mu = 750$

Alternative hypothesis: $\mu \neq 750$

$t=\frac{811-750}{\frac{19.647}{\sqrt{5}}}=6.943$

$p_v =2*P(t_{4}>6.943)=0.00226$

If we compare the p value and a significance level assumed $\alpha=0.05$ we see that $p_v$ so we can conclude that we reject the null hypothesis, and the actual true mean is significantly different from 750 pounds per hour.

Step-by-step explanation:

Data given and notation

Data: 801, 814, 784, 836,820

We can calculate the sample mean and sample deviation with the following formulas:

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

$s=\sqrt{\frac{\sum_{i=1}^n (X_i -\bar X)^2}{n-1}}$

$\bar X=811$ represent the sample mean

$s=19.647$ represent the standard deviation for the sample

$n=5$ sample size

$\mu_o =750$ represent the value that we want to test

$\alpha$ 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 to be tested

We need to conduct a hypothesis in order to determine if the mean is different from 750 pounds per hour, the system of hypothesis would be:

Null hypothesis: $\mu = 750$

Alternative hypothesis: $\mu \neq 750$

Compute the test statistic

We don't know the population deviation, so for this case 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".

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

$t=\frac{811-750}{\frac{19.647}{\sqrt{5}}}=6.943$

Now we need to find the degrees of freedom for the t distirbution given by:

$df=n-1=5-1=4$

What do you conclude?

Compute the p-value

Since is a two tailed test the p value would be:

$p_v =2*P(t_{4}>6.943)=0.00226$

If we compare the p value and a significance level assumed $\alpha=0.05$ we see that $p_v$ so we can conclude that we reject the null hypothesis, and the actual true mean is significantly different from 750 pounds per hour.

4 0

3 years ago