Pls help this is for a test

Sunspots have been observed for many centuries. Records of sunspots from ancient Persian and Chinese astronomers go back thousan

Lunna [17]

Answer:

(a) Null Hypothesis, $H_0$ : $\mu$ $\leq$ 41

Alternate Hypothesis, $H_A$ : $\mu$ > 41

(b) The value of z test statistics is 1.08.

(c) We conclude that the mean sunspot activity during the Spanish colonial period was lesser than or equal to 41.

Step-by-step explanation:

We are given that in a random sample of 40 such periods from Spanish colonial times, the sample mean is x¯ = 47.0. Previous studies of sunspot activity during this period indicate that σ = 35.

It is thought that for thousands of years, the mean number of sunspots per 4-week period was about µ = 41.

Let $\mu$ = mean sunspot activity during the Spanish colonial period.

(a) Null Hypothesis, $H_0$ : $\mu$ $\leq$ 41 {means that the mean sunspot activity during the Spanish colonial period was lesser than or equal to 41}

Alternate Hypothesis, $H_A$ : $\mu$ > 41 {means that the mean sunspot activity during the Spanish colonial period was higher than 41}

The test statistics that would be used here One-sample z test statistics as we know about the population standard deviation;

T.S. = $\frac{\bar X-\mu}{\frac{\sigma}{\sqrt{n} } }$ ~ N(0,1)

where, $\bar X$ = sample mean = 47

σ = population standard deviation = 35

n = sample of periods from Spanish colonial times = 40

So, the test statistics = $\frac{47-41}{\frac{35}{\sqrt{40} } }$

= 1.08

(b) The value of z test statistics is 1.08.

(c) Now, the P-value of the test statistics is given by;

P-value = P(Z > 1.08) = 1 - P(Z < 1.08)

= 1 - 0.8599 = 0.1401

Since, the P-value of the test statistics is higher than the level of significance as 0.1401 > 0.05, so we have insufficient evidence to reject our null hypothesis as it will not fall in the rejection region due to which we fail to reject our null hypothesis.

Therefore, we conclude that the mean sunspot activity during the Spanish colonial period was lesser than or equal to 41.

8 0

3 years ago

David is making rice for his guests based on a recipe that requires rice, water, and a special blend of spice, where the rice-to

Elodia [21]

Answer:

The price of rice per gram is 0.006$

Step-by-step explanation:

I. David wants to make 10 servings,

each require 75 g of rice and 5 spice. When ratio is 15:1

If rice : spice = 75 : x

15x = 75

x = 5

=> 5 * 15 : 1 * 5

= 75 : 5

So rice : spice is 75 : 5

II. When 1 serving require 75 : 5

So 10 servings is 10 * 75 : 5 * 10

= 750 : 50

So he must has 750 grams rice and 50 grams spice.

III. He must buy spice and rice which..

a) He has 40 grams spice, he'll buy for 10 grams spice.

b) He has no rice, he'll buy for 750 grams rice.

But the question only ask for price of rice which he spend 4.5$

= $\frac{4.5}{750}$

= 0.006$

In 1 gram of rice he spend 0.006$

If 750 grams of rice, he'll spend 750 * 0.006$ = 4.5$ => true

That makes 0.006$ is the right answer.

Hope that help :)

8 0

3 years ago

You start driving west for 20 miles, turn left, and drive south for another 14 miles. At

pogonyaev

Answer:

About 24.4

Step-by-step explanation:

3 0

3 years ago

Ryan has a rope that is 3 yards long. Her brother gave her another rope that is 4 yards long. She needs 20 feet of rope to play

mr Goodwill [35]

Answer:

Yes

Step-by-step explanation:

7 yards of rope is the same as 21 feet of rope. The required amount of rope is 20, meaning that it is possible to play double dutch.

6 0

2 years ago

Do you flip the inequality sign, yes or no? Explain why –5x < 35

Ivahew [28]

Answer:

yes you flip the sign because you are diving by a negative

4 0

3 years ago