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1 year ago

Michael goes shopping. At the start of his shopping trip he has

Mathematics

1 answer:

fredd [130]1 year ago

4 0

Answer:

Micheal has £6.97 left

Step-by-step explanation:

6 × £0.32 = £1.92

2 × £1.09 = £2.18

£9.69 + £1.92 + £2.18 = £13.79

£20.76 ‒ £13.79 = £6.97

More description not a valid question.

6 0

2 years ago

A safe has a 4-digit lock code that does not include zero as a digit and no digit is repeated. What is the probability that the

uysha [10]

Answer:

The probability is found:

P = 24/3024 = 1/126

Step-by-step explanation:

To find total number of outcomes, we have to find permutation of 9 things taken 4 at a time:

P(9,4) = 9! / (9-3)!

P(9,4) =362880/120

P(9,4) = 3024

Number of even numbers from 0 to 9 = 4

To find desirable number of outcome, find permutation of 4 things taken 4 at a time.

P(4,4) = 4! / (4-4)!

P(4,4) = 24/1

P(4,4) = 24

The probability that the lock consists of all even digits is

P = No. of desirable outcomes / No. of total outcomes

P = 24/3024

3 0

2 years ago

We're testing the hypothesis that the average boy walks at 18 months of age (H0: p = 18). We assume that the ages at which boys

marusya05 [52]

Answer:

II. This finding is significant for a two-tailed test at .01.

III. This finding is significant for a one-tailed test at .01.

d. II and III only

Step-by-step explanation:

1) Data given and notation

$\bar X=19.2$ represent the battery life sample mean

$\sigma=2.5$ represent the population standard deviation

$n=25$ sample size

$\mu_o =18$ 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)

2) State the null and alternative hypotheses.

We need to conduct a hypothesis in order to check if the mean battery life is equal to 18 or not for parta I and II:

Null hypothesis: $\mu = 18$

Alternative hypothesis: $\mu \neq 18$

And for part III we have a one tailed test with the following hypothesis:

Null hypothesis: $\mu \leq 18$

Alternative hypothesis: $\mu > 18$

Since we know the population deviation, is better apply a z test to compare the actual mean to the reference value, and the statistic is given by:

$z=\frac{\bar X-\mu_o}{\frac{\sigma}{\sqrt{n}}}$ (1)

z-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".

3) Calculate the statistic

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

$z=\frac{19.2-18}{\frac{2.5}{\sqrt{25}}}=2.4$

4) P-value

First we need to calculate the degrees of freedom given by:

$df=n-1=25-1=24$

Since is a two tailed test for parts I and II, the p value would be:

$p_v =2*P(t_{(24)}>2.4)=0.0245$

And for part III since we have a one right tailed test the p value is:

$p_v =P(t_{(24)}>2.4)=0.0122$

5) Conclusion

I. This finding is significant for a two-tailed test at .05.

Since the $p_v$ . We reject the null hypothesis so we don't have a significant result. FALSE

II. This finding is significant for a two-tailed test at .01.

Since the $p_v >\alpha$ . We FAIL to reject the null hypothesis so we have a significant result. TRUE.

III. This finding is significant for a one-tailed test at .01.

Since the $p_v >\alpha$ . We FAIL to reject the null hypothesis so we have a significant result. TRUE.

So then the correct options is:

d. II and III only

6 0

2 years ago

Which function could be shown in the graph below

defon

Answer:

quintic function

Step-by-step explanation:

3 0

2 years ago

Raul is practicing for baseball tryouts he wants to find how far he can hit a baseball he hits the ball 10 times and measures th

wel

Answer:

See Explanation

Step-by-step explanation:

Given

$n = 10$ --- Number of tryouts

Required

Determine the average distance

This question has missing details, as the distance he hits the ball in each tryout is not given. However, I'll give a general explanation.

The mean is calculated as:

$\bar x = \frac{\sum x}{n}$

$\sum x$ means the sum of the distance in each tryout.

Assume that the distance in the 10 tryouts are: $6, 8, 5, 9, 4, 5, 8, 7, 7, 6.$

So, the mean is:

$\bar x = \frac{6+ 8+ 5+ 9+ 4+ 5+ 8+ 7+ 7+ 6}{10}$

$\bar x = \frac{65}{10}$

$\bar x = 6.5}$

So, the average distance is 6.5

4 0

1 year ago

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