Air crew escape systems are powered by a solid propellant. the burning rate of this propellant is an important product characteristic. specifications require that the mean burning rate must be 50 centimeters per second. the experimenter selects a random sample of n=40 and obtains an observed sample mean of the burning rate 51.3 centimeters per second and an observed sample standard deviation of the burning rate 2.0 centimeters per second. based on a 5% type i error threshold, construct a hypothesis test and draw your conclusion.

Conclusion: Reject the mean of 50 cm/sec and establish a new mean of 51.3 cm/sec

Step-by-step explanation:

In this case we can set our hypothesis the following way:

:The mean burning rate equals 50 cm/sec.

: The mean burning rate is greater than 50 cm/sec.

So this is a right-tailed hypothesis test.

For a 5% level of significance, the Z-score against with we are going to compare is (the area under the normal curve N(0;1) to the right of Z is less than 5%)

We compute the Z score corresponding to the sample with the formula

where  

= mean of the sample

mean of the null hypothesis

s = standard deviation of the sample

n = size of the sample

Computing our Z, we get

Since our Z is greater than , we reject the null hypothesis and we could also state a new mean equals to the alternative, that is to say, we could say that the mean is 51.3 instead of 50.

2. angles qrt and qst both measures 156 degrees.

step-by-step explanation:  

we have been given a diagram of a circle and we are told that measure of arc qvt is 156 degrees.  

we can see from our given diagram that angle qrt and angle qst subtends to arc qvt.

since we know that angles subtended by the same arc at the circumference are always equal.

by angle subtended by same arc theorem, measure of angle qrt and angle qst will be equal to the measure of arc qvt.

therefore, angles qrt and qst both measures 156 degrees and 2nd statement is the correct choice.

the answer is (-8,-5)

step-by-step explanation:

the endpoint to midpoint is half the length. the length is (-2,-1) so when you are at the midpoint just add it to it to find your answer -6+(-2)= -8 and -4+(-1)=-5 so (-8,-5)