hypothesis test

#1
True or False: Referring to the table below, the null hypothesis will be rejected.
TABLE
An appliance manufacturer claims to have developed a compact microwave oven that
consumes an average of no more than 250 Watts. From previous studies, it is believed that power consumption for microwave ovens is normally distributed with a standard deviation of 15 Watts. A consumer group has decided to try to discover if the claim appears true at .05 level of significance. They take a sample of 20 microwave ovens and find that they consume an average of 257.3 Watts.
 

Dason

Ambassador to the humans
#2
Hi! :welcome: We are glad that you posted here! This looks like a homework question though. Our homework help policy can be found here. We mainly just want to see what you have tried so far and that you have put some effort into the problem. I would also suggest checking out this thread for some guidelines on smart posting behavior that can help you get answers that are better much more quickly.
 
#3
I have got the following


z-value 2.1764
one-tailed p-value 0.0148

95% confidence internvals
upper Inf
lower 244.483

Reject Null

True

Is the ans correct?