It should me b I don’t know if it is but it should be
Answer:
35°
Step-by-step explanation:
Angles on a straight line add up to 180, so 180-145 is equal to
The simple answer (not using multiples of 2

(360°)) is
Answer:
a
The null hypothesis is

The Alternative hypothesis is

b

c

d
Yes the mean population is significantly less than 21.
Step-by-step explanation:
From the question we are given
a set of data
20 18 17 22 18
The confidence level is 90%
The sample size is n = 5
Generally the mean of the sample is mathematically evaluated as


The standard deviation is evaluated as



Now the confidence level is given as 90 % hence the level of significance can be evaluated as

%

Now the null hypothesis is

the Alternative hypothesis is

The standard error of mean is mathematically evaluated as

substituting values


The test statistic is evaluated as

substituting values


The critical value of the level of significance is obtained from the critical value table for z values as

Looking at the obtained value we see that
is greater than the test statistics value so the null hypothesis is rejected