Please help i dont know which one

It is advertised that the average braking distance for a small car traveling at 65 miles per hour equals 120 feet. A transportat

olga nikolaevna [1]

Answer:

We conclude that the average braking distance for a small car traveling at 65 miles per hour equals 120 feet which means that the statement made in the advertisement is correct.

Step-by-step explanation:

We are given that it is advertised that the average braking distance for a small car traveling at 65 miles per hour equals 120 feet. A transportation researcher wants to determine if the statement made in the advertisement is false.

She randomly test drives 36 small cars at 65 miles per hour and records the braking distance. The sample average braking distance is computed as 114 feet. Assume that the population standard deviation is 22 feet.

Let $\mu$ = average braking distance for a small car traveling at 65 miles per hour.

So, Null Hypothesis, $H_0$ : $\mu$ = 120 feet {means that the average braking distance for a small car traveling at 65 miles per hour equals 120 feet}

Alternate Hypothesis, $H_A$ : $\mu\neq$ 120 feet {means that the average braking distance for a small car traveling at 65 miles per hour is different from 120 feet}

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 average braking distance = 114 feet

$\sigma$ = population standard deviation = 22 feet

n = sample of small cars = 36

So, test statistics = $\frac{114-120}{\frac{22}{\sqrt{36} } }$

= -1.64

The value of z test statistics is -1.64.

Since, in the question we are not given with the level of significance so we assume it to be 5%. Now, at 5% significance level the z table gives critical values of -1.96 and 1.96 for two-tailed test.

Since our test statistics lies within the range of critical values of z, 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 average braking distance for a small car traveling at 65 miles per hour equals 120 feet which means that the statement made in the advertisement is correct.

5 0

4 years ago

Film travels through a projector at the rate of 170 feet per minute. How many feet of flim are in a motion picture that last 120

Vaselesa [24]

120x170=20400

hope it helps

6 0

3 years ago

The Asteroids played the Constellations. Each team scored 1

Valentin [98]

Answer:

Asteroids won

24 - 23

Step-by-step explanation:

First Quarter = Asteroids 3 - 3 Constellations

Field goals are 3 points

Second Quarter - Asteroids 9 - 10 Constellations

Touchdowns are 6 points

Extra Point is 1 Point

Third Quarter - Asteroids 16 - 20 Constellations

Fourth Quarter - Asteroids 24 - 23 Constellations

5 0

4 years ago

What would a persons speed if they travelled 394 meters in 94 seconds?

VladimirAG [237]

Distance = speed* time

distance = 394meters, time = 94 seconds

speed = distance/time
= 394/94
= 4.191 m/s

7 0

3 years ago

A magazine has 1,620,000 subscribers, of whom 640,000 are women and 980,000 are men. Thirty percent of the women read the advert

Kaylis [27]

Answer:

Expected number of subscribers in the sample who read the advertisements=42

Step-by-step explanation:

Step 1

Determine the proportion of both men and women subscribers as shown;

Proportion of Men subscribers=number of men subscribers/total number of subscribers

where;

number of men subscribers=980,000

total number of subscribers=number of men+number of women

total number of subscribers=(980,000+640,000)=1,620,000

replacing;

proportion of men subscribers=980,000/1,620,000=98/162

Step 2

Proportion of women subscribers=1-(98/162)=64/162

Step 3

Expected proportion of men that read the advertisement=(50/100)×(98/162)=4,900/16,200=49/162

Expected proportion of women that read the advertisement=(30/100)×(64/162)=1,920/16,200=192/1620

Step 4

Total number of proportion=(49/162)+(192/1620)=341/810

Expected number from the sample=(341/810)×100=42

Expected number of subscribers in the sample who read the advertisements=42

3 0

3 years ago

Please help i dont know which one​

Please help i dont know which one